In computer terms, a memory stick is a small, portable electronic storage device. Memory sticks are mostly used in portable devices, like digital cameras, to store electronic data. In the case of a digital camera it will store photographs. Most modern computing devices, for example computer laptops, have ports where you can plug in the memory stick to download or copy the data from the memory stick to the computer.
The term memory stick was first created by Sony to describe their flash memory devices but today, the term memory stick, is used to describe these types of devices in general.