ESOL is similar to ESL. It can be compared with EFL, which refers to learning and using English as an additional language in a non-English speaking country.
Example
There are many ESOL projects in countries such as the UK or US, where there are immigrants from non-English speaking countries.
In the classroom
ESOL classes can include areas such as survival English, functional language, specific speaking and listening skills, and sociocultural information. They often have an element of citizenship training also.
Further links:
https://www.teachingenglish.org.uk/article/exploring-uk-esolefl-divide
https://www.teachingenglish.org.uk/article/choosing-using-resources-esol-learners
https://www.teachingenglish.org.uk/article/teaching-reading-esol-classroom