What is caching in unity (what is it)?

Question

C++ / C#

Hello, I recently came across "caching" in unity to reduce the load on the PC. I searched, looked, saw many ways to cache some data (this is the first thing I didn’t understand, is there any standard? Maybe it’s all the same way, but with a different record?). Previously, I managed to write data to arrays, lists, queues, separate files, sometimes the registry. How does a recorded cache differ from all of the above? Where is it stored and does it need to be cleaned and deleted separately if the need for the created game is gone?
A big THANK YOU in advance!!!

Answer 1

Caching is the name for this approach, when instead of creating some expensive objects every time, you create or find them 1 time and reuse them.
What exactly was meant in those guides that you found is unknown.