ESOL stands for English for Speakers of Other Languages and is an SQA National Course aimed at Senior Phase Pupils for young people who speak English as an Additional Language. It is offered at :

National 2, SQA ESOL National 2 Course Overview

National 3, SQA ESOL National 3 Course Overview

National 4,SQA ESOL National 4 Course Overview

National 5 (exam) SQA National 5 Course Overview

Higher level (exam)  SQA Higher ESOL Course Overview

and it focuses on developing key language skills of speaking, listening, reading and writing. 

Further Resources 

Excellence Gateway. You will find a lot of great support resources, success stories and information about living in the UK at Excellence Gateway website ESOL Excellence gateway 

The Bell Foundation (free membership) ESOL programme offers a wide range of resources for ESOL students with the focus on developing life skills; form filling, conversations at the GP etc. Check their website for further resources at The Bell-Foundation