Cache is a smaller and fast memory component in the computer which is inserted between the CPU and the main memory. Cache memory is extremely fast memory and it resides within the processor chip (CPU). The main aim is to try to fill it with the data which might be needed again soon.
The cache must know where the information stored in a cache line originates from in main memory. It uses a directory store to hold the address identifying where the cache line was copied from main memory.
The size of a cache is defined as the actual code or data the cache can store from main memory.
Registers
Register are the smallest holding data elements that are built into processor itself. These are memory locations that can be directly accessible by processor. A register is basically a storage space for units of memory that are used to transfer data for immediate use by the CPU for data processing.
The register memory indicates the capacity of the register to hold the size of data it can hold. The capacity varies on the design of the processor and varies for example a 32-bit microprocessor can have 8-bit register giving memory size 256 bits. There are many types of registers like Accumulator, Data Register, Program Counter, General purpose, etc. Thus they can be used for various tasks.
