It Means Continue Mission. Usually said after an interruption or hiccup in whatever you're doing. This phrase is derived using the phonetic alphabet (Military Alphabet). Instead of saying Continue Mission, Charlie Mike is said instead so everyone over the radio can understand and know what you mean.
By using the first letter of each word and converting that to the Military Alphabet you get the phrase charlie mike.
C = Charlie M = Mike
Chef Mike is a term used in the restaurant industry to describe restaurants that do not have chefs who actually cook, but only use a microwave. Many examples are shown in low-rated restaurants.
John: Dude, the only chef in that damn restaurant is chef mike!
George: Guess we aren't going there.
Bijuu Mike (aka Michael) is a funny guy who does YouTube videos on knock off games, Yandere Simulator, reactions to awesome animations that his fans make, etc. People love him because of his awesome personality and for being himself.
Thank you Bijuu Mike for caring about other people and making them happy!