1 Record or upload your video. 2  At the end of the video processing stage in the upload interface, you will see an option to choose a Custom thumbnail under the Video thumbnails section. 3  Go to your channel Video Manager. 4  Locate a video and click the Edit button. 5  Click the Custom thumbnail button and upload a thumbnail.
Median is the middle number of a given dataset (if itÃÂ­s odd) while average is a definition of arithmetic mean, which is the most oft-cited average. The value of median depends on the number of elements in a data set (odd or even) while average does not.
The difference between Mean and Average is that the term Mean is used more in Statistics and the term Average is used more in Arithmetic. But there is no rule which prohibits the vice versa use which means that Mean can also be used in Arithmetic and Avg if used in Statistics can not be termed as wrong.