Micro PCs

A miniature PC, Mini PC or Smart Micro PC is a small-sized, inexpensive, low-power, legacy-free desktop computer designed for basic tasks such as Internet surfing, accessing web-based applications, document processing, and audio/video playback.

A stick PC is a dongle running an operating system. When placed in the HDMI port of a television or a monitor, this device turns that display into a personal computer. These often allow adding a keyboard or mouse over Bluetooth or Wi-Fi.
(Wikipedia)