Transformations
A data source retrieves data in a specific format. A visualization panel, in its turn, requires a particular format as well. If those two formats do not match, transformations can help to find the common denominator.

Where to find more information and examples
Our YouTube video and blog post provide everything you need to grasp the Grafana transformations concept.
Video
In the video, you can follow Daria in her step-by-step demonstration.
Blog post
The blog post covers the same ground. In addition, it also illustrates when transformations help to avoid the dead end.
We added them following the question from the community - why transformations are needed at all. So, if you ever wondered that, the answer dwells in the following post.

All Grafana transformations
We did not describe nor explain every single available Grafana transformation. We thought that giving a conceptual view is enough.
If there is any transformation in particular that gives you a hard time, you can leave a comment under our Transformations in Grafana YouTube video and we will see what we can do.