Your laptop will have either USB 1.0 or USB 2.0/2.2. Most laptops around are not 1.0 anymore but the 1.0 and 2.0/2.2 are different speeds.

Firewire is the new version of USB. It has a lot faster transfer rates but it is a little more expensive.

E-Sata is the newest and the fastest. It is a port that is only used for HD's. Newer computers have these inside the case for your HD. Even newer computers will put another port for X-HD's outside of your machine.

If you post your model number of your pc I can tell if you have Firewire or E-Sata.