Which network cable to choose? How does speed depend on length? Which category is better?

Question

Iron

1. What is the correct name of the network cable? I heard different names: patch cord, and twisted pair, and just a network cable. And I don't know how to do it right.
2. What does the cable category affect?
3. How strong will the speed loss be with a cable length of 20 meters? Will there be delays (like high ping)? In fact, it is desirable not to be, because I choose a cable as an alternative to Wi-Fi due to large losses in speed (from half and above).
4. Will it handle a 50 megabit connection?
5. What price is considered acceptable per meter of cable?
6. RJ 45. This is a connector, right? Is there a difference in these connectors? Maybe there are different versions or different contacts (copper, gold plated)? Does it affect speed?

Answer 1

1. The cable is called "twisted pair category X", where X is 3, 5 and 6. Now 5 is widespread.
2. For speed. Range everywhere - no more than 100 meters. Category 3-100 megabits, 5-1000 megabits, 6 - 10,000 megabits, but no further than 5 meters.
3. No. There will be no noticeable delay, it will be less than a millisecond.
4. A cable even of the third category gives guaranteed 100 megabits.
5. 12 - 15 Russian money.
6. No, this is a stupid delusion. RJ-45 generally will not fit into the network connector due to the additional protrusion. Correctly the connector is called 8P8C.
In your home case, a category 5 cable is enough (okay, a third one is enough, in which there are two pairs, not 4, but it is difficult to crimp it) and ordinary plastic connectors without a screen. We are not building a data center.