Single satellite multiroom satellite TV systems up to 4 rooms or 3 rooms including a Sky+ or Freesat+ receiver can use a quad universal LNB (octal LNBs are available but the number of cables at the dish can be unsightly).
Multi dish, multiroom systems serving more than 3 receivers are best provided using multiswitches (see below).
If the satellites are close together then 1 dish with multiple LNBs can be used. For example Astra 28E, Astra 19E and Hotbird 13E are able to be received by one dish whereas Astra 28E and Eutelsat 5W would need 2 dishes.
2 or more satellites and 4 or more receivers are best provided using multiswitches (multiswitches are available with 4, 8, 12, 16, 24 and 32 outputs).
Multiswitches also allow terrestrial TV, FM and DAB radio signals to be combined in a single cable to each room by using a special outlet called a triplex plate.
DisEqC switches are used to switch the receiver between the different satellites. Multiswitches have these switches incorporated into them. For simple multi satellite systems one DisEqC switch is required for each receiver (2 are required if feeding a plus box).
Please note that Sky and Sky+ boxes cannot be used in multi satellite systems as they do not support satellite feed switching. If you are using Sky subscription services a second receiver is needed for the alternative satellite(s). If just viewing free-to-air satellite channels on Astra 28E then a TNTSat or FranSat box may allow viewing of Freesat channels as well.