Dissenters, in Scotland, are those who belong to (presbyterian) denominations that have broken away from the (presbyterian) Church of Scotland. They are not the same as English Dissenters who broke away from the Church of England, so the Wikipedia article is not relevant to this thread.
The term 'non-conformist' pre-dates the union of Parliaments in 1707, and specifically means someone who refuses to conform to the Act of Unity passed by the English Parliament in 1662. Therefore it has no meaning in relation to Scotland. All denominations in Scotland except the Episcopal Church of Scotland would have been non-conformists in relation to the 1662 Act if it had applied to Scotland, which it doesn't.
The list of dissenting denominations is many and varied: Auld Lichts, New Lichts, Burghers, Antiburghers, Cameronians, Bereans, Secession Church etc, all of which existed in the 18th century. In the 19th and 20th century there were others: Free Church, Free Presbyterian Church (often known as Seceders), United Presbyterian, Reformed Presbyterian to name but a few. And in the 21st century there are umpteen more separate denominations; too many to mention.
And then, of course, there are the separate denominations like the Society of Friends (Quakers), Baptists, Methodists etc, and non-Christian religions like Judasim.
From the point of view of family historians, the point to note is that not all the surviving registers of dissenting denominations are available at Scotland's People. The vast majority are, but some are either not held by the National Records of Scotland, or the congregations who own them have not given permission for them to be digitised.
