SATA stands for Serial Advanced Technology Attachment. It's the interface that connects storage devices, like hard drives and solid-state drives, to your computer's motherboard. The standard replaced the older PATA (Parallel ATA) technology and has remained largely unchanged since its introduction in the early 2000s.
A SATA connection actually involves two separate cables: a data cable (thin and flat) that transfers information between the drive and motherboard, and a power cable that supplies electricity to the drive. The connectors are L-shaped and keyed, meaning they only fit one way, so you can't plug them in incorrectly.
There are three versions of SATA in common use. SATA II maxes out at 3 Gbps, whilst SATA III (also called SATA 3.0) offers 6 Gbps. Most modern drives use SATA III, though the speeds are rarely the limiting factor for everyday use. A newer variant, M.2 SATA, uses the same 6 Gbps protocol but fits into a different physical slot on the motherboard, taking up less space.
For example, if you're adding a second hard drive to an older desktop computer, you'll plug a SATA data cable into a SATA port on the motherboard and connect the drive's power via a SATA power connector from your power supply.
When buying a new drive or a replacement computer, check whether you need SATA compatibility. Most traditional hard drives still use SATA, and it remains reliable for everyday storage. However, M.2 NVMe drives are becoming more common and offer faster speeds, though they cost more. If your motherboard has M.2 slots and your budget allows, NVMe is the better choice for speed; otherwise, SATA remains a solid, affordable option.