Personal digital assistant

A personal digital assistant (PDA) is a handheld computer. Personal digital assistants were designed to replace non-electronic day planners. They became widespread in the 1990s. Many PDAs can work as an address book, a calculator, a clock, and a calendar. Some also have games on them. The work of PDAs is now mostly done bysmartphones that use Wi-Fi and touch screens for e-mail, recording video, playing music and making phone calls.

PDA's processor is a chip which makes the device work. PDAs can have different processors depending on their speed. If access to the Internet, GPS, or video recording are needed, the PDA needs to have a fast processor.

Memory

PDA stores data and applications on RAM memory(Random Access Memory). It is a memory card inside the device. PDAs can also use SD (Secure Digital), SDIO and MMS cards. These are easy to remove and are called flash memory cards. USB flash drives can be used to add more memory.

Memory capacity guide
16MB	can contain simple data such as contacts and text files.
32MB	allows to use e-mail and office programs.
64MB	can access Internet and play video, images, music.
128MB+	recommended for Internet access, makes PDA work better, and easily plays music, images and video (multimedia).

Screen

Most PDAs have touch screens. This means that the device has less buttons or has no buttons at all. Usually PDAs come with removable 'pen' (stylus) with which the screen is touched. The pen acts like a mouse for desktop PCs or like a touch pad for laptops. For other PDAs a finger is used instead of the pen.

Battery

PDAs are powered by batteries. There are two types of batteries: removable and fixed. Older PDAs used alkaline batteries which the user would have to take out and replace when they ran out. Most new PDAs have Li-ion batteries. These batteries are rechargeable. PDAs use more battery power when playing video, accessing Internet or transferring data using Bluetooth. Large and bright screens also take more power. This makes the battery run out faster.

Connection

A PDA can communicate with other devices, PDAs, PCs, etc. This is made with the help of infrared (IrDA) port or with Bluetooth. With this ability the devices can transfer data, download music, images, video, games, etc.

Synchronization means having the same data on both the PDA and PC or other device. When changes are made on either the PDA or the PC, when they are synchronized, these changes made to data on one of them are also made the data on the other. The synchronization also prevents the loss of the stored information.

Adaptation (Customization)

Customization is adding more memory, miniature keyboards, etc. to the PDA. Customization also can be putting other software (download Internet programs) on the PDA device.