Computer Type

Excuse my ignorance, I am just learning.
If I need to carry a computer to manage my daily schedule of meetings, which should I choose: a. personal server, b. PDA, c. personal computer, d. Laptop

OK, I don’t think carrying my PC is going to work for the obvious reasons. I don’t know what a personal server is. I wouldn’t mind a laptop so much. Is the answer “PDA”? I don’t own one and don’t really know what they are capable of.