The Raspberry Pi is a low cost, tiny credit-card sized computer that can be whatever you want it to be. It encourages people of all ages to learn how to program and create interesting things. It is capable of basic desktop computer tasks, like browing the internet, word-processing, and playing games, but it also can be used in a wide array of maker projects. It's been used for weather stations, tweeting birdhouses with infra-red cameras, and music machines. It's a great way to gain a better understanding of how computers work.
Recently, the Raspberry Pi 3 was released with updated specs. It now has a 1.2GHz 64-bit quad-core ARM Cortex-A53 CPU, and integrated 802.11n wireless LAN and Bluetooth 4.1. It has 1GB of RAM and support for microSD cards. Connectivity options on the device include an HDMI port, a 3.5mm analogue audio/video jack, 4 USB 2.0 ports, a Camera Serial Interface, and Display Serial Interface.