Imagine you are in a classroom with your teacher and some other kids. Your teacher speaks to you in a language you can understand, like English. This is called the medium of instruction. It is the way teachers communicate with you and how you learn.
Some kids might speak a different language at home, like Spanish or French. If the medium of instruction is English, they might have a harder time understanding what the teacher is saying because they are used to hearing a different language at home.
That's why some schools have different mediums of instruction, like Spanish or French. This means the teacher will speak to the students in those languages, so they can understand better.
It's important to have a medium of instruction that everyone can understand, so they can learn and do well in school.