During' is followed by a noun, which often represents an activity (during + the film). 'While' is used to refer to a background period of time in which another activity happened. It is very similar to during, but it is followed by a sentence (while + subject + verb...) Note:- The words 'During' and 'While' are not interchangeable.

yah.

prepared yourself about everything on cv

it is a word used to connect clause and sentences....... i.e and, if, but etc.