Ram Charan plays body double?

In Ram Charan’s current movie, Bruce Lee The Fighter, he enacts the role of a stunt master. That is what we all know, but in actual he plays the role of body double. What exactly is a body double?
 
In film industry business, stars (male/female) recruit someone who resembles like them in height and look to perform risky action stunts in their place. Charan will be playing such a role in the film. The film despite being based on film industry is a family entertainer and the focus will be on comedy.
 
Chiranjeevi has a key scene to play in this film. We are told that it is a fun scene. DVV Danayya is producing the film and music is by Thaman. Rakul Preet has been paired with Ram Charan. Srinu Vaitla is making the movie on grand scale with comedy and family values.