Laptop memory is designed to help your system run faster and smoother. Laptop memory modules are organized into DDR, DDR2 and DDR3 and the more modern DDR4. These are the most widely recognized and used types. When buying and choosing replacement memory modules, you have to take into consideration the motherboard's compatibility and the type of memory to buy. If your laptop only accepts one type of memory, for example DDR2 or DDR 3, you cannot upgrade to DDR3 or DDR4 memory. To upgrade to any other memory type, you will either have to replace the motherboard or buy a new computer. Memory types are not interchangeable.