In Absolute Block, tokenless block or token working areas - which are those in which semaphore signals are mainly used - the starter signal (or section signal as it is officially known nowadays) is the last signal controlled by a given signalbox to be encountered by a driver before entering the section ahead to next box. It's known as a section signal because it controls entry to a block section. Sometimes the signal at the end of a station platform may be colloquially referred to by station staff as the 'starter', but this is not always the case. For example, in a situation on a double line where there is a crossover beyond the platform 'starter', there will have to be another stop signal further in advance, to prevent trains which have crossed over from one line to another from entering the section when it is occupied. In such a case, the stop signals between the distant signal and the section signal will be known as 'Home 1', 'Home 2', etc. - depending on how many of them there are. The first (and sometimes only) home signal encountered by a driver after passing the distant signal, is so-called because it protects a train which is already in the station. Sorry if this sounds rather complicated....it's much easier to explain with the aid of a diagram, but I don't know how to append one here. If you can get hold of the book "British Railway Signalling" by G.M. Kitchenside and Alan Williams, it is well-explained in there, with clear and simple diagrams.