back up portable hard drive for my acer aspire laptop

[dim wit]

i have an acer aspire laptop v5-571p and i want to back my computer up ,if it breaks down,can i buy any suitable external hard drive

 

[R_1]

as long as the external drive is large enough (at least 750 GB) to store the data you need and the interface is compatible USB 3.0
I suggest a 2.5 inch form factor as there will only be one cable. the external will be powered by the laptop.
most important: USB 3.0
important: capacity
optional: 3.5 inch will need external power (wall wart) 2.5 inch will be laptop powered