, there have been 387 seasons of Big Brother in over 54 franchise countries and regions.In the show, contestants called "housemates" (or "house guests") live together in a specially-constructed house that is isolated from the outside world.
Most international versions of the show remain quite similar to each other: their main format remains true to the original fly on the wall observational style with the emphasis on human relationships, to the extent that contestants usually are forbidden from discussing nominations or voting strategy.
In 2001, the US version adopted a different format during its second season, where the contestants are encouraged to strategize to advance in the game; in this format the contestants themselves vote to evict each other.
However, the UK version introduced a larger number of contestants with weekly evictions.
Most versions of Big Brother follow the weekly eviction format, broadcast over approximately three months for 16 contestants.
In some countries, Internet broadcasting was supplemented by updates via email, WAP and SMS.
The house is shown live on satellite television, although in some countries there is a 10–15 minute delay to allow libelous or unacceptable content (such as references to people not participating in the program who have not consented to having personal information broadcast) to be removed.
In more-recent series, contestants are occasionally allowed to view televised events (usually as a reward for winning at a task).
In most versions of the program, books and writing materials are also forbidden, although exceptions are sometimes made for religious materials such as the Bible, Tanakh or the Qur'an.
The program also relies on other techniques, such as a stripped back-to-basic environment, evictions, weekly tasks and competitions set by Big Brother, and the "Diary Room" (or "Confession Room") where housemates convey their private thoughts to the camera and reveal their nominees for eviction.