This is a group of plain trick games with a characteristic order of cards in the trump suit. Above the ace of trumps are the two bowers (from the German Bauer, which means farmer and is one of the normal German words for a jack). The right bower is the jack of the trump suit, and immediately below this is the left bower, which is the other jack of the same colour.
Some versions are played with a joker, formerly known as the best bower and now more often as the benny. In fact it was for use in Euchre that the joker was first added to the standard American deck in the mid 19th century. The word "joker" itself is derived from "Euchre" or "Juker". In Britain the spade two is often used as the benny, rather than an actual joker.
Basic Euchre is played with a short pack, formerly 32 or 33 cards, but 24 or 25 cards in modern versions. Just 5 cards each are dealt to the 4 players, and the aim is to win at least 3 of the 5 tricks. There is a simple process for choosing trumps: each player in turn has the opportunity to accept the suit of the turned up card, and if all reject there is an opportunity to choose another suit.
There are several more elaborate games based on Euchre. In some more cards are dealt to the players and there is bidding in which the team that offers to win more tricks is allowed to choose trumps. In this way they are similar to games of the Boston group.