Celebrity Big Brother is a spin-off of the British reality television series Big Brother, broadcast in the UK and Ireland. Originally broadcast on Channel 4 and E4, and later on Channel 5 and 5Star, and ITV1 and ITV2 respectively, it involves a group of celebrities, called housemates, living in isolation from the outside world in a custom-built "house".[1][2][3][4] The actions of the participants are recorded constantly by microphones and cameras situated in each room.[2] Regularly, the housemates nominate two other members of the group each to face eviction; those with the most nominations face a public telephone vote, and the housemate who receives the most public votes is evicted.[2] This procedure continues until the final day, when the viewers vote for who of the remaining participants they want to win the programme.[3] Profits from premium-rate telephone votes are donated to charities such as Comic Relief, Centrepoint and Samaritans.[5][6]