info: Computer Hardware components. In general , you have to consider the following : Ram (memory), processor, hard disk storage, display adapter and video memory. Most equipment now comes with wireless connectivity for internet access, some with bluetooth. Physical ports (or sockets) typically include external keyboard, mouse, monitor, HDMI, and ethernet( for cabled network connections).
Cheaper equipment generally has less RAM, and slower processors. This is rarely a problem if you will only be doing work processing, however any kind of multimedia, video , graphics , games, etc. can suffer, so always keep the suggestions in step 1 in mind.
Info: Computer Software. Keep in mind that the computer is a means to an end, and for most people this means software over and above the programs that come with the computer. There are vast numbers of programs around including freeware (free to download and use) shareware (where you pay a license fee) and of course commercially available software. My advice here is research the available options and ensure the programs you choose do the job you want.