“Laughter is an instant vacation,” said the comedian Milton Berle, so it is small wonder that situation comedies, or sitcoms for short, take up a huge chunk of airtime on many TV channels.

Featuring a small cast of characters who share a particular environment, the sitcom can be defined as a kind of comedy soap opera. Though each episode has a self-contained story, there is also an overall story arc, which develops over a season, allowing characters to develop and relationships to flourish. Witty dialogue creates most of the laughs, but characters are also often put in compromising situations or tripped up with physical humor.

Some sitcoms are filmed in front of a live audience, but this laughter can also be simulated with the use of a laughter track, which is added to the soundtrack later. This highlights the moment when a joke occurs and provides a comedic and comfortable atmosphere.

The most well-known American sitcom is probably Friends, which follows the lives and relationships of six New Yorkers. Over the course of 10 seasons, airing between 1994 and 2004, the characters became loved by millions of fans, and the show was known for its sharp gags and accessible humor.

The sitcom that has made the biggest waves over the last decade though is The Office—a two-season British sitcom that was filmed in the style of a documentary about normal British office life. This revolutionary sitcom focused the humor on darker elements such as embarrassment, self-delusion, and repressed desires, and abandoned the customary laughter track altogether.

An interesting development in the form of the sitcom is that currently many popular sitcoms are ones in which the main characters are simply slightly altered or exaggerated versions of the primary actors. For example the British comedians Rob Brydon and Steve Coogan recently made a sitcom called The Trip, in which the main characters are comedians called Rob Brydon and Steve Coogan who go on a restaurant tour of northern England together. Whereas sitcoms like Friends presented the audience with an idealized comedic world, this unusual kind of sitcom is now blurring the line between the world of TV and the black comedy of real life.

喜劇演員米爾頓伯利曾說：「歡笑是一場立即的假期」。因此，情境式喜劇，或簡稱情境喜劇，在許多電視頻道中掀起一陣風潮，也不令人意外。

情境喜劇的特徵是少數人物身處在特定場景中，也可說是喜劇肥皂劇的一種。雖然每集都有獨立的故事，但仍有貫穿全劇的整體性，在每一季中逐漸增溫，使人物能夠建立角色特色，角色關係也能繁盛發展。風趣的對話帶出多數的笑點，除此之外，角色們也常身處必須妥協的情境中，或是犯些小錯，以動作表達幽默。

有些情境喜劇是在現場觀眾面前拍攝的，但還是可以在聲音後製時，加上罐頭笑聲音效來冒充現場觀眾。笑聲強調了玩笑的發生時點，也提供一個有喜感又舒服的氛圍。

最廣為人知的美國情境喜劇大概就屬《六人行》，劇中描述六位紐約客的生活與彼此的關係。橫跨十季，由1994播放到2004，上百萬粉絲熱愛這些人物，本劇也因尖銳的玩笑和容易理解的幽默而打出知名度。

在過去十年間掀起最大風潮的情境喜劇，仍非《辦公室笑雲》莫屬，該劇為兩季的英國情境喜劇，以紀錄片方式拍攝平常英國辦公室的生活。這部革命性的情境喜劇著墨於較曖昧晦澀的幽默元素，如陷入窘境、自欺欺人，以及壓抑的慾望，此劇也捨棄慣用的罐頭笑聲。

情境喜劇形式的有趣發展是，目前許多熱門情境喜劇將角色設定為主要演員的修飾版或誇大版。舉例來說，英籍諧星羅伯．布萊頓和史帝夫．庫根，最近就合拍了一部名為《旅程》的情境喜劇。劇中主角就是兩個名為羅伯．布萊頓和史帝夫．庫根的喜劇演員，一起踏上北英格蘭的餐廳巡禮。相對於像《六人行》這樣的情境喜劇所呈現理想化的喜劇世界，這種不尋常的情境喜劇模糊了界線，讓電視世界和現實生活的黑色喜劇之間不再涇渭分明。