A computer term for a handheld device that combines computing, telephone/fax, and networking features. PDA examples include the Palm and Pocket PC devices. A typical PDA can function as a cellular phone, fax sender, and personal organizer. Unlike portable computers, most PDAs are pen-based, using a stylus rather than a keyboard for input. This means that they also incorporate handwriting recognition features. Some PDAs can also react to voice input by using voice recognition technologies. Some PDAs and networking software allow companies to use PDAs in their warehouses to support wireless transaction processing and inquiries.