These two conjunctions are both translated as “and” but the difference is in their usage. Look at the examples and try to figure out when we use each one.
As you can see, we use “и” when we have same things. Look at the example 2 – she is saying, “I am Maria and that’s Maria too“. When we have something different we use “а“. Look at the example 1: She is saying, “I am Maria and that’s Max.” (Max is a different name from Maria).
Also you should know that we use the conjunction “а” at the beginning of question sentences like:
А: Как вас зовут? – What is your name?
Б: Ирина. А вас? – Irina. And your?