Scots is actually it's own language, one that's older than English but it's a language that's changed a huge amount and has constantly adapted with the predominant languages of the area. It was originally a Celtic language with Gaelic being the Highlanders language even to this day. As influences from other parts of Britain have moved into the area like with the migration of the Irish in the 18/19th century new words are developed and the language continues to grow and live. The variation of influences plays a lot in the dialect of each area with words being common across the whole of Scotland to half of it to specific regions. For a country so small the language is amazingly dynamic and vibrant.