A TLB (Translation Lookaside Buffer) is a hardware cache that is used in computer systems to improve the efficiency of virtual memory management. It stores recently accessed virtual-to-physical address translations, eliminating the need to access the page table for every memory access. TLBs are typically implemented in the memory management unit (MMU) of a processor.

The TLB works by storing a subset of the page table entries (PTEs) that map virtual addresses to physical addresses. When a memory access is made, the MMU first checks the TLB. If the virtual-to-physical address translation is found in the TLB, it is used directly, bypassing the slower access to the page table. This is known as a TLB hit. If the translation is not found in the TLB, it results in a TLB miss, and the MMU accesses the page table to retrieve the translation. The retrieved translation is then stored in the TLB for future use.

The TLB improves the Effective Access Time (EAT) of memory operations by reducing the time required for address translation. Without a TLB, every memory access would require accessing the page table, resulting in additional memory accesses and increased latency. By caching frequently used translations in the TLB, subsequent memory accesses that require the same translation can be performed much faster, reducing the overall memory access time.

The TLB's ability to store and retrieve address translations quickly significantly improves the EAT by reducing the overhead of address translation. It helps to minimize the impact of memory latency on system performance, particularly in systems with large virtual address spaces and frequent memory accesses.