A mobile device (also known as cellphone device, handheld device, handheld computer or simply handheld) is a pocket-sized computing device, typically having a display screen with touch input or a miniature keyboard. In the case of the personal digital assistant (PDA) the input and output are combined into a touch-screen interface. Smartphones and PDAs are popular amongst those who require the assistance and convenience of a conventional computer, in environments where carrying one would not be practical. Enterprise digital assistants can further extend the available functionality for the business user by offering integrated data capture devices like barcode, RFID and smart card readers.
Handheld devices have become ruggedized for use in mobile field management situations to record information in the field. They are used to achieve a variety of tasks for increasing efficiency that include digitizing notes, sending and receiving invoices, asset management, recording signatures, managing parts and scanning barcodes. Handheld computers used at work have molded over time into a variety of form factors, including smartphones on the low end, handheld PDAs, Ultra-Mobile PCs and Tablet PCs. Laptops do not come under handheld computers as they are not small enough to hold in one's hand.