A _________IS AN AREA OF HIGH SPEED MEMORY THAT SITS BETWEEN THE PROCESSER AND THE PRIMARY MEMORY.
The term you are looking for is "cache." A cache is an area of high-speed memory that sits between the processor and the primary memory (usually RAM) in a computer system. Its purpose is to store frequently accessed data and instructions so that the processor can access them quickly, without having to fetch them from the slower primary memory.
To get the answer to this question, you can search for the term "area of high-speed memory between processor and primary memory." This will lead you to resources that explain what a cache is and its role in a computer system.