Read?mostly memory

What is the meaning of the term (when applied to memory systems technology)?

Memory that is non?volatile (retaining data when powered down) is called read?only memory. However, most forms of this memory have two problems. First, a write cycle often takes very much longer than a read cycle (making random access operation impossible) and second, the number of write cycles to each
cell is limited because writing data physically damages the cell. Consequently, the memory is called readmostly because it may be accessed frequently but written to occasionally.