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CompTIA A+ Core 1 220-1201 · Domain 3: Hardware

RAM: DDR4 vs DDR5, DIMM vs SODIMM, single, dual and multichannel, ECC, virtual RAM

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Last reviewed September 30, 2026 · Leer en español

RAM (random access memory) is the fast, temporary workspace where the CPU (central processing unit) keeps the programs and data it is using right now. It is volatile, so its contents disappear when power is removed. Too little RAM is one of the most common causes of a slow computer, and choosing the correct type is a frequent A+ question, because memory that looks similar is often not interchangeable at all.

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