"As" means exactly the same. "Like" means similar to, but not exactly the same.

Very good explanations above. Two more examples: Ex. 1: I work LIKE a slave. But I am NOT a slave. Ex. 2: He works AS a slave, And he IS a slave.

Like --> Like is used as a preposition and should be followed by a noun Ex.: "It's hot in this room. It's like an oven!" - Both an oven and this room are hot Ex.: "She works in a hotel, like me." - We both work in a hotel. As --> As is used to compare something that is the same as something else, or in the same condition. Use a subject and a verb after as. Ex.: "As I told you, the meeting started at 3pm." Ex.: "It rained all weekend as we thought it would."