laptop i7 specs
DDR laptop memory, otherwise known as DDR1 (though this isn't an official name instead referred to as just DDR) or DDR SDRAM is the oldest and slowest. It's predominantly available in capacities up to laptop i7 1GB (per module) and at speeds of up to 400MHz (effective).
DDR2 is an evolution to DDR with some internal enhancements to boost performance and usually available in capacities up to 2GB...