Data Flow between Data Glue and S3 bucket

Hi Everyone,
I have one basic question related to Data Glue. In week 1 assignment, we are creating database and table (review). These only contains information related to database and table column type or schema info. It means there is no data in table.
Data is present in s3 bucket.

But when we are writing SQL query then only we are using info from Data Glue not from s3 bucket so how query is fetching data. How they are linking?

I have the same question. When i query the table ‘reviews’, the result df shows empty