Cache is used by the CPU. It reduces the time needed to access the data from the main memory.
Cache memory is faster and smaller, it is located near the processor core and stores copies of data frequently used by the main memory.
If you do not clear the cache memory it will make everything slower
However if you do not clear the cache memory it will not have any major effect on your computer
Cache memory is everywhere from operating systems to phone apps and browsers.
CPUs depend on the cache to to do all the calculations, CPU require data stored in cache memory to do faster calculations.
Cache used in browsers speeds up the repeat visit visits to web pages.
Well developed applications are able to clear cache at any time and still keep functioning until cache is rebuilt, but sometimes the data stored on Browser cache can cause login issues so we should clear the browser cache to prevent it.