Multifunction Printer, or Separate Printer and Scanner?
An MFP combines print, copy, scan, and sometimes fax capabilities into one device. While there's very little an MFP can do that a separate printer and scanner couldn't do, an MFP saves space and offers more-coordinated functionality. This combination is especially attractive for personal use, for small or home-based businesses, and even for busy satellite or executive offices. Early models tended to look clunky, but currently available choices can be as sleek or as burly as you wish. A standard inkjet model should be adequate for home, student, and small-office use; a laser unit (either monochrome or color) or a high-end inkjet model will address an office's need for speed and flawless text quality. Laser models, especially the color ones, still tend to cost a great deal more.
Office-oriented MFPs have an automatic document feeder (ADF) for scanning multiple pages as a single task, and they often have a built-in fax machine and ethernet or Wi-Fi networking. Photo-oriented models sometimes let you scan slides and negatives, and they usually have built-in media slots for reading from digital camera memory cards. It's usually a good idea to give yourself room to grow if you can: Spend the extra bucks for a model with a larger paper tray, or splurge on a unit with an ADF so you aren't stuck feeding multiple pages onto a flatbed scanner.
PC World does not test an MFP's fax features. Such functions add to the price, and many documents are now acceptable as e-mailed PDFs. If you don't need to fax, don't pay for these features.