LKS2, UKS2 - what does this mean?

[Ruled]

Having a browse on twinkl to download some activities for my 10 year old - primary 6 in Scotland.

Some of the activities are labelled UKS2 or LKS2 - google is not helping me find out what these mean!

Year 5 is equivalent to primary 6 AFAIK.

Lower key stage 2 (years 3&4) and upper key stage 2 (yrs 5&6)

Upper KEy Stage 2 and Lower Key stage 2 possibly?

England KS2 is years 3 - 6

You know that's so bloody obvious - thank you