Hi Mary,
There are three dialects of Gaelic - Manx, Scottish and Irish - all derive from Ireland, and from the 'Celtic' group of languages, which includes Welsh and Breton as cousin languages.
Manx Gaelic is all but extint, though some revivalists on the Isle of Man are trying to get it up and running again. usually referred to as 'Manx' or (and I think this is right) 'Galik'.
Irish Gaelic is more commonly referred to as 'Irish', 'Gaelic' (pronounced 'Gaylick') or 'Gaeilge'.
Scots Gaelic or Scottish Gaelic is more commonly referred to as 'Gaelic' (pronounced 'Gallic'), or 'Gaidhlig'.
Gets a bit more confusing than that though! There's other lesser dialects, so Irish Gaelic on Rathlin Island (north of Antrim), is almost like Scots Gaelic with some words spelt in Irish; Ulster Gaelic is very similar to Scots Gaelic as well, whilst Manx Gaelic looks like Gaelic that would be written down by a Welshman! lol
The language of 'Scots' though is a cousin to the English language, being of the 'Germanic' language group. It's also known as Lallans (Lowlands), Doric (in the east of Scotland), and others such as Ullans (Ulster Lallans - taken to Ireland by Scottish lowlanders in the 17th C plantations). Words like 'kirk', Scots for a church, can be found in other Germanic languages - for example 'kirche' in German itself, but in Gaelic it would be a completely different word - 'eaglais' (pronounced 'eglish').
Bottom line though is that with a good stiff whisky or three, you can easily become fluent in any of them!!!
Chris