As and like are two words that are often confused. Both can be prepositions or conjunctions.
As a preposition, like means similar to, especially when we compare appearance or behaviour:
Who do you look like? Your mother or your father?
I look like my mum because I have blond hair and blue eyes. However, I’m not like her because we have very different personalities – she is very calm and I am very nervous.
Like also means in the same way as:
Like my sister, I am studying medicine because I want to become a paediatrician.
As means in the role/capacity of and is often used to talk about jobs:
When he finished his degree in architecture he worked as a waiter for three years before he managed to find a job as a project manager in a construction company.
When used as a conjunction as and like have the same meaning when used to make a comparison. Like is more informal:
My husband loves sushi, as/like I do.
My brother has his That’s English! class on Monday, as/like I do.