Always-on e-mail Synonymous with push e-mail, this service automatically sends e-mail to your wireless device, rather than requiring you actively to check a service or site to determine if you have new e-mail.

Bluetooth A wireless technology specification for transmitting voice and data across a global radio frequency band among computer devices within a 30-foot range of each other.

Character recognition A data-input feature that converts hand-drawn symbols to digital format and then to alphanumeric characters, symbols, or device navigationand control commands. Recognition technologies such as Palm OS's Graffiti alphabet permit data input and navigation without a keyboard.

Docking cradle A device used to connect a handheld to a PC for synchronization and application downloads. The two are connected via the handheld's communication port using a serial or USB cable. The cradle often doubles as a battery charger as well.

Expansion slot The opening in a handheld where standard cards or modules can be inserted to enhance its feature set. Options include adding storage memory, connectivity solutions (such as network cards and wired or wireless modems), GPS units, cameras, MP3 players, applications, and content such as e-books and music.

Handheld A portable device for storing and managing personal information. The available features depend on the type of handheld you choose. In general, the term is interchangeable with PDA (personal digital assistant). More specifically, handhelds refer to electronic organizers, H/PCs, Palms, and Pocket PCs.

Infrared beaming The process of using the IrDA standard to transmit data wirelessly from one device to another, even if their OSs differ. Beaming is a near-effortless way to exchange records and applications between handhelds or transmit files to an infrared-enabled printer. It's also possible to use some digital phones as modems via an infrared connection.

Operating system (OS) A program that is burned or recorded in ROM and controls a handheld's feature set navigation, and interface. A widespread standard OS, such as Palm OS or Windows CE, offers more extensive support for third-party applications than a proprietary OS.

Personal information manager (PIM) A program for organizing contacts, appointments, tasks, and notes. Choose a handheld with a PIM that synchronizes with your desktop's personal organizer software.

Random access memory (RAM) The segment of a handheld's memory that stores data and applications. In some handhelds, all data in RAM is lost when the battery power drains.

Read-only memory (ROM) The segment of a handheld's memory that stores the OS and built-in applications, which cannot be changed or deleted. If ROM is flashable, you can upgrade the OS via a file download from a PC and access any unused storage via a third-party application.

Stylus A penlike device for navigation and data input. In most cases, a handheld has a secure slot for storing a stylus; it's a good idea to carry an extra one.

Synchronization The process of exchanging data between a handheld and PC so that changes are reflected on files stored in both computers. The most advanced synchronization programs support customization and access via various connections, including serial and USB ports as well as network, dial-up, and wireless connections.