I'll start of with the beautiful word beta.
Beta is actually the second letter of the Greek alphabet. It looks like this β. Related to technology, beta or a beta version is the second (occasionally third) release of a software.

Illustration from wikipedia.
Beta versions is generally speaking the first version to be unveiled for the public. The main reason of releasing a beta version of a software is to let testers (also known as beta testers) try out the software before it’s given / sold to the public. In that way, the developers spend less time themselves testing out a product, and can at the same time develop a software with fewer bugs.
That was it for this first “episode” of What is.
If you have something to apply to this post, please feel free to do.