Like and as are often confused in English. They can both be used to talk about how things are similar.
Like is followed by a noun or pronoun. For example, "I'm like my sister", or "Like my sister, I have brown eyes."
When we use "like" in this way, we can describe physical similarity as well as similarity of character.
"I'm like my sister. We both have dark hair."
"I'm just like my sister. I hate it when people are rude."
If you want to ask for a description of a person, you can say:
"What's she like?" (i.e. is she nice or difficult to get on with?)
If you want a physical description of a person, you can say:
"What does she look like?" (is she tall, or does she have brown hair, for example?)
If you want to find out who a person resembles (either physically or in character) you can say:
"Who is she like?" (does she take after her mother or her father, for example?)
You can use "look like" to talk about physical similarity.
"She looks like her aunt. They both have red, curly hair."
(Be careful that you don't confuse the two, and say something like "I'm look like" or "She's look like".)
You can also use "look like" to make a prediction.
"It looks like it's going to rain."
"She looks like she's going to cry."
"He looks like he's about to go on holiday."
"It looks like it will be a great year for the company."
As is followed by a subject and verb. For example, "She's a good student, as her brother was before her."
However, in spoken English, like is often used instead of as. "She's a good student, like her brother was before her."
As is used with a preposition, such as, "As in the 1960's, the population explosion will cause some problems."
We can use as in certain expressions, such as "as you know", "as you requested", "as we agreed".
We also use as.....as to give comparisons. For example, "He's as clever as his sister."