Codenames is a board game designed by Vlaada Chvátil and released by more that 25 different publishers around the world. It is a word-based game, and while being a great game, can be a bit slow-paced and/or difficult if you are not a wordnerd. Because of this, Chvátil has released a number of pictorial versions, along with other variations for different tastes and gameplay.
The original game was played by laying out 5 X 5 grid of cards with words on them, and having 'spymasters' give clues to help their team find the target words. The team that finds all of their codewords first wins; guessing the wrong word is never good, but you especially don't want to uncover the opposing team's words, and one card will be an 'assassin', which causes the team that uncovers it to lose instantly.
To set up the game, each team picks a spymaster, and the two spymasters sit across the table from the spies. The spymasters have a key that tells them which of the cards on the table are the red team's codewords, the blue team's, the neutral words, and the assassin. The spymasters take turns giving a single word clue, and the number of cards it applies to; e.g., if the spymaster wanted their team to guess the words 'cake', and 'cream', but absolutely not 'donut', they could give the clue "bands, 2". The spies would make their guesses, the results announced, and play would move to the other team... who would now be under pressure to give a clue identifying at least three words if they want to take the lead.
The base game is quite fun, and I highly recommend it. It is easy to learn, but gameplay can be a bit slow (thinking up good clues is hard!), and many people looking to play board games are looking for something a bit snappier. So... we have Codenames: Deep Undercover (contains naughty words!), Codenames: Duet (a two-player variant), Codenames: Pictures, Codenames: Harry Potter (pictures, but they're all screenshots from the Harry Potter films!), Codenames: Marvel (you guessed it!), Codenames: Disney, Codenames: The Simpsons... you get the idea. I personally don't like the pictorial versions as much as the language-based ones, but the pictures in Codenames: Pictures are both simple and charmingly surreal, making it worth checking out.