Charades is a parlour game where the participants take it in turns to mime a particular name of a subject (typically a film, song, book or similar item) and the others try to guess the item. The player miming is not permitted to speak and can only use gestures and body movements to attempt to convey the name of the item - usually against a time limit
For instance, Bob might be trying to get the name of the film Star Wars guessed. He would start by using the universal sign for a film (cranking an old fashioned hand camera). He would then hold up two fingers to indicate a two word answer, then one finger to indicate he was about to demonstrate the first word If he was outside at night (assuming a clear sky) he might point to a star. If he was inside he might grab his ear (means "sounds like") and pantomime driving a car (this could result in wrong guesses such as "Driving!", "Racing" or similar. Once someone guessed the first word, he would hold up two fingers to indicate the second word and then pantomime warfare - holding an imaginary machine gun and spraying imaginary bullets, hurling imaginary grenades etc. Once someone successfully guessed the name (or time ran out) another player would take over with a new name (either the sucessfully guessing player or the next person in sequence).
Pictionary is a similar idea but rather than miming, players draw a representation of the name onto large sheets of paper instead. They are not allowed to use letters or numbers as that would render the game too easy.