Memory access refers to the process by which a computer retrieves or stores data in its memory. This involves using specific addresses to locate data within the computer's memory hierarchy, which includes RAM, cache, and hard drives. Efficient memory access is crucial for a computer's performance, as it determines how quickly data can be read or written. There are different types of memory access methods, such as sequential access and random access. In sequential access, data is read in a specific order, while random access allows the computer to access any memory location directly. Understanding these methods helps in optimizing data retrieval and storage processes.