Captain Marvel vs Shazam?

Whats the story with these two? They the exact same guy?

So who is the dude in red? Is it Captain Marvel or is it Shazam?

Its Capt Marvel..

Technically, the super-hero in the red outfit with the lightning bolt and the white cape is not SHAZAM. SHAZAM is the egyptian wizard who grants Billy Batson the ability to transform himself into Captain Marvel.

Part of the confusion regarding the name SHAZAM is that "SHAZAM" is a much more distinctive name than "Captain Marvel". Marvel Comics have had a number of characters of the name "Captain Marvel" and hold the current trademark on the name. Thus, DC's Captain Marvel comics are published under the title of SHAZAM

SHAZAM==S= Soloman's wisdom,H=Hercules Strength,A=Atlas Stamina,Z=Zeus's Power,A=Achilles's Courage M=Mercury's speed..

Shazam!!!..LOL

So why did he yell Shazam to turn into the superguy? I find this rather confusing, lol

Does the dude in red go by the name Shazam as well? Or is he just Captain Marvel?

Basically, he yelled "Shazam" to turn into Captain Marvel. Comic readers began referring to him as Shazam.