Answer / greenborhan

RAM>>>Random Access Memories are read/write memories in which data can be written into or read from any selected address in any sequence but When a data unit is written into a given address in the RAM, the data unit previously stored at that address is replaced by the new data unit.

ROM>>>Read Only Memory that contains permanently or semi permanently stored data, which can be read from the memory but either cannot be changed at all or cannot be changed without specialized equipment.

In very short,
1. RAM is volatile (i.e. it forgets everything after power off), but ROM is non-volatile (i.e. it can remember the stored data after power off)
2. RAM can store data for a very short time which can't use repeatedly in system applications but ROM stores data for long time which can use repeatedly in system applications, such as tables, conversions or programmed instructions for system initialization and operation.
3. Data stored in RAM is erased automatically after power off but to erase/rewrite stored data in ROM special equipments are needed, such UV ray.

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