In laptops, you can expand the capabilities of a computer with a number of different expansion ports. These include ExpressCard adapters, SO-DIMM memory modules, USB flash drives and Thunderbolt connectors. The ports are all made smaller to fit in slimmer laptops with fewer internal components. They have also changed shape, with different numbers and configurations of pins. The differences help make them suitable for different types of hardware and generations of technology.
The earliest laptops used a VGA port, which connected to external monitors or projectors and supported up to 648x480 pixels of video resolution. This type of expansion port isn't used much anymore, as most laptops have built-in displays that are more portable and have better graphics.
Today's laptops use a variety of USB ports to connect keyboards, mice, printers and external hard drives. You can also use a SD card reader for storing digital photographs and other files on the go. There's even a new form of storage for slim laptops called an M.2 drive, which has a small size and can hold more NAND chips than traditional SSD drives for increased capacity.
The easiest way to upgrade the RAM in a laptop is by inserting a new module into an empty slot on the motherboard. The slots are often covered by covers, and the modules have clasps on each end that snap in when plugged in. They can be installed in pairs, and are sometimes color-coded for identification. The slots may have a plastic cover to protect the memory from moisture or dust. The modules are also known as SIMMs, which stands for single in-line memory module. The original DIMM memory modules had 168-pin connectors, but they have since been replaced by a smaller version called a SO-DIMM that has a 32-bit data path to the CPU and requires less space than a full size DIMM.