A lot of vs. Lots of
A lot of and lots of are used to express that there is a large quantity of something.
We use a lot of in positive sentences, negative sentences and questions. This expression can be used with countable or uncountable nouns.
There are a lot of dogs in the street. (Countable noun)
I have a lot of time to answer your questions. (Uncountable noun)
I saw a lot of people waiting in the queue. (Countable)
We did have a lot of fun, didn't we? (Uncountable)
We use lots of in positive and negative sentences, however it is more informal. It can be used with countable or uncountable nouns, and occasionally in questions.
We have lots of time to catch the plane, lets relax. (Uncountable noun)
There are lots of people in the queue today. (Countable)
Oh my, you have spent lots of money on clothes! (Uncountable)
I have lots of questions. (Countable)
She has a lot of money = She has lots of money