Prior to newer forms of dynamic random access memory (DRAM), FPM DRAM (Fast Page Mode DRAM) was the most common kind of DRAM in personal computers. Page mode DRAM essentially accesses a row of RAM without having to continually respecify the row. A row access strobe (RAS) signal is kept active while the column access strobe (CAS) signal changes to read a sequence of contiguous memory cells. This reduces access time and lowers power requirements. Clock timings for FPM DRAM are typically 6-3-3-3 (meaning 3 clock cycles for access setup, and 3 clock cycles for the first and each of three successive accesses based on the initial setup).
For other forms of RAM, see our Fast Guide to RAM.