2 NVMe connection. M2. SSDs tend to be faster than SATA SSDs, but on the whole, they are both much faster than hard drives. Here is a 1TB internal SATA SSD which can fit in 2.5-inch drive bays.
Luckily 1 TB, 2 TB, and even 4 TB drives are still ... These are slower than NVMe drives but they're still a huge improvement on a traditional hard drive.