There are chemicals called “aerosol” that are a liquid when contained in pressure. When you release the pressure they expand into a gas and accelerate out of the can, pushing the other contents out with them. If you flip a can upside down and spray it you may see frost forming on a surface you aim it at, or you'll feel a can get cold the longer you spray cause it's the exact same mechanic that allows your air conditioning to work. This is compared to using compressed air which would need a much sturdier container, it's why the walls of air compressors are so thick

The same with numpad without the dot bellow the plus key, usually they put a larger plus key and that's it but I really like the dot and it's harder to find

It's not terribly complicated. The contents of the can are under pressure. There's a valve on top of the can. When you open the valve, some of the contents come out because fluids flow from high pressure to low pressure.

Thank you, kind Redditor.

With u/FilthyWeasle 's, u/zhonzhon 's, and your explanation, I understand a little bit better.

Not really.

u/FilthyWeasle , u/AcusTwinhammer and u/zhonzhon do explain better.

Thank you so much, kind Redditor.

I think I understand a little bit better now. Yes, your explanation is better than Wikipedia and even my teacher. But no, I can't pay you. Not because I don't want to, but because I don't have money.

Again, thanks.

EV batteries don't use rare earth metals. They're used in the motors, but not because they're strictly necessary, they just make for more efficient and compact motors.

But yeah, car-centric cities become deserts: https://www.youtube.com/watch?v=uxykI30fS54

>As an european, I WANT more parking space, I would love to drive anywhere, including downtown, without worrying where to park, I want 6 lanes on the highway each direction. I would never accept using anything else than my own car.

>Especially considering the rise of electric vehicles and the inevitability of dropping fossil fuels altogether, why is the idea of "build a city around the pedestrians, bikes and public transport" being so forced?

The whole point of a car is to enable you to quickly travel medium and large distances. That makes it rather pointless in a city where a public transit system can fulfill the same role more efficiently while all medium to short distances can also be traveled by bike.

Using up precious city space on the truly tremendous (and often redundant) amounts of infrastructure needed by cars when public transit and bike lanes can deliver the same throughput at a much tinier footprint is just wasteful and city planners are starting to take that into account.

Congestion is a huge issue.

A single subway train can carry hundreds of people, nearing a thousand.

Now imagine how much road will be required to get a thousand cars to some place. How wide the roads will need to be, how many people need to be displaced to fit it. How loud it's going to be for those who remain.

Parking is an issue.

Now imagine, how much parking you'll need to house a thousand cars. It's a building that does nothing but house cars. You need to clear land, it's going to block views and take up space.

Equity is an issue.

Now think on those people too poor to afford cars. All those opportunities to get ahead will be lost to them due to their inability to get around. The deck was stacked against them already, now they have an additional disadvantage.

Environmental issues are another issue.
Think of the energy needed to repeatedly move a thousand car weights every day for hours. That isn't coming for nowhere, even green energy like solar or wind has up keep and wilderness habitat displaced. It's far better than fossil fuels, but not zero. Also think of all the manufacturing for a thousand cars, the tons of metal needed for the bodies, the tons of rare-earth elements for the batteries and electronics. That is if we do go green and electric, more likely it will be all fossil fuels for a long time.

Oh and that single train carrying a thousand people. Several of those will be going every hour for rush hour.

The USA has a reputation for creating urban hellscapes thanks to its car centric approach. You do not want that for your country.

Because Induced Demand exists and so it will always be impossible to build enough transit infrastructure to solve congestion... and private cars are the most expensive, least scalable, most damaging, least equitable and socially isolating mode of transit to build more infrastructure for.

Most places in Europe just don't have the space/luxury to "spread out" like North American cities (which were built much, much later than those in Europe were). There is still a lor of land available for development in North America (specifically the US). Or, the places that have parking and/or large multilane roads were built fairly recently on open land. For parking lots and multilane highways in places Europeans want/need to go, they'd have to tear down what's already there

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You can do those things in Europe?

Just not everywhere in Europe. Europe allows cities and towns to exist without being entirely built around cars.

Parking takes up space, a whole bunch of real estate that could be used for something else.

There are not enough rare earth metals to make the batteries to replace all of the cars in the US much less the entire planet.

Internet -> Modem -> Router config xD

Router: A router is a device that forwards data packets between computer networks. It is connected to two or more networks, such as the Internet and a local area network (LAN). Routers use headers and forwarding tables to determine the best path for forwarding the packets, and they use protocols such as ICMP to communicate with each other and configure the best route between any two hosts. Modem: A modem is a device that modulates an analog signal to encode digital information,

Router vs Modem vs Access Point: A router is a device that forwards data packets between computer networks. It can also act as a firewall to protect your network from malicious activity. A modem is a device that modulates and demodulates signals for data transmission over telephone lines or other communication mediums. An access point is a device that allows wireless devices to connect to a wired network using Wi-Fi, Bluetooth, or similar technology. Switch vs Bridge vs Hub

so basically, there are devices that

1. repeats traffic it gets, ie it broadcasts to everyone connected to it, and also used for extending ranges. ie the repeaters and hubs. and range extenders for wireless.
2. devices that routes traffic to where it needs to go, ie only the specific device connected gets the traffic. ie switches, and access points for wireless.
3. devices that connect networks together, ie a local area network to a wide area network or two different wide area networks. ie routers
4. devices that converts one signal format to another signal format, ie analog to digital or digital to analog or coax to wifi, or whatever. . ie modems and transceivers

so basically using the postal service analogy. your post office is a router. all your mail goes through your post office. mail intended for an address not serviced by your post office is delivered to another post office (and that post office figures out where it needs to go). the mail delivery man is like the switch. they connect to your post office (router) and deliver the mail to your door. now a days, hubs/repeaters are typically not used anymore because that's like everyone in your post office delivery area getting everyone's else's mail as well, but you just throw away mail not intended for you.

This is a very technical question. It’s hard to answer this in an ELI5 format.

A network is a bunch of computers connected. How they’re connected is called the “topology” of the network.

Imagine one group of computers connected in one “network”. Now, imagine a second network. These two computer networks can’t just talk to each other if you put a cable between them. They won’t know (generally speaking) how to talk to each other. A router is a device that spans two networks, and is a “gateway” that passes stuff from one network to another.

That’s why your home router is called a “router”. It connects the ISP’s incredibly complex network that runs outside with the little itty bitty network in your house.

A modem is short for “modulator/demodulator”. That used to make more sense when “home modems” were devices which “sang notes” on the public telephone networks. The modulation was the “singing”, the “demodulation” was the “hearing” of the “notes” and interpreting it as data. Today, “modems” decode other types of signals, because often the type of signal from the ISP’s incredibly complex network is not the same kind of network in your house, nor is it the same “song and notes” from phone-based networks. So, your home router will also have a modem inside.

“Home routers” is a huge misnomer. It’s a gigantic smashing of all kinds of network devices bundled together into one appliance.

A “bridge” connects two networks, as well, like a router, except that it’s “more basic”, in that the two networks it connects become one bigger network. This is a technical distinction that’s hard to understand without a lot more detail. You will almost never encounter a bridge.

An “access point” almost always means “wireless access point”. It’s what allows your non-wired devices to talk to your network. In the past, these were separate things. But, in your home router, they will add that functionality all into the same box.

A switch and hub are similar. They are the “switchboard”, and allow computers to connect, forming the “network”. Again, this would be another separate device, but your home router has a switch built-in.

You’re mixing together wired terminology with wireless terminology, and that makes it harder to talk about. An AP (access point) is almost always referring to a wireless AP.

A “transceiver” is short for “transmitter/receiver”. Anything qualifies here. A modem qualifies. A wireless AP qualifies. A tin can connected to another tin can by a string qualifies. Your head qualifies (mouth makes sounds, ear hears sounds, brain does all the computational work). Any networked device must have some kind of transceiver; otherwise, it turns into a black box.

A “repeater” is exactly what it sounds like. It’s a transceiver that hears something, and then shouts it again. Imagine you’re trying to get your dad’s attention. But he’s outside. But your mom is in the kitchen. So, if she hears you yelling for your dad, she can then yell your command, and your dad might her yelling because she’s closer. Repeaters can be wired or wireless, although in most contexts, it’s meant to be wireless.

Range extenders are just repeaters, and almost always refer to wireless repeaters.

So, your home “router” does a lot of stuff in one box. A more complex network, say, with hundreds or thousand of hosts is going to need that stuff broken up into lots of separate boxes, for performance and management and security reasons.

If you want diagrams, I charge $225/hour to my corporate clients. Or, just go back to wikipedia/Google with these basic definitions, and try to work it from there.

> There may be some use cases for hubs still, but generally they should be avoided.

There is no such thing as a hub for modern wired Ethernet anyway; Gigabit Ethernet requires switches and full-duplex links.

(One thing we used to use hubs for is security monitoring: run your Internet traffic through a hub and attach the intrusion detection system(s) there; since the hub mirrors all traffic to all ports, your IDS can sniff it all. These days you'd use a network tap or a span port for that.)

Router: Routes packets at the IP level.

Switch: Routes packets at the layer 2/MAC address level.

So a packet going out gets to a router, the router decides by IP address where that packet needs to go. If that IP address is "local" to the router, that is in a subnet the router has ownership of, it then uses switching to send the packet to the destination. Most modern routers have some switching capability, and most switches have some routing capability.

Hubs: Really dumb switches. A switch will keep track of connected devices, so if a packet is going to destination MAC aaaa.bbbb.cccc.dddd, it knows that MAC is on port 7 and sends it to that port. A hub does not keep track of such things and just sends the packet to every connected port. There may be some use cases for hubs still, but generally they should be avoided.

Bridge: generally a point to point link of some kind. For example, if you have two office buildings, the main one has the main network, but the second one needs to connect but you can't run any sort of standard ethernet arrangement, you might set up some sort of point-to-point wireless bridge connection.

Modem: Changes signal type. For example, cable internet does not use ethernet. So the cable modem is what changes the ethernet packets to the DOCSIS protocol on the cable coax.

Access Point: WiFi. Is the communication point for end devices using WiFi to talk to the network. Wireless broadcast, so arguably more of a hub than a switch in such terms.

Transceiver: The physical component in a router or switch that is turning the packets into flashes of light on the fiber line.

Repeater: If your signal has to go a long distance on the wire, it may not be strong enough to make it. So a repeater will just take the signal coming in and blast it out the other. The bonfires between Rohan and Gondor are repeaters.

Range Extender: I generally hear this with WiFi, essentially trying to do the same thing as a repeater, but it's sometimes a little more complicated since WiFi is broadcast radio.

a) For an ELI5, this is like asking for a full course in the "basics" of networking. Too much

b) It is technical. There is no way around it. It is like asking for a lesson in quantum mechanics without referencing physics. Not really meaningfully possible.

c) There are logical functions (translation of symbols/information) and physical hardware and then actual products (which incorporate a variety of functions and physical hardware). Think of it as a home address (logical/symbolic) vs the home (physical) and the postal service (a combination of using logical function and physical to provide a service). Without a clear appreciation of the differences (again technical), it would be hard to explain all the things you asked.

A starting point might be the OSI model to understand the conceptual framework of networking and communications. Then the various functionalities etc will make sense.

Welcome to the wonderful world where us non-US keyboard layout users have been living for decades:

The game says, press "[". Sometimes I can press the key where "[" is on an US keyboard. Sometimes I can type "[" by pressing AltGr+8 in my language. Sometimes neither works (because the game doesn't know about AltGr, and I interprets it as "right alt") and I'm just unable to use this particular control.

And another one. Did you both just ask chatGPT or what?

This answer has nothing at all to do with the question.