A schema is a collection of logical structures of data objects. A schema is associated with a database user and has the same name as that user. Each user have a single schema. Schema is mainly collection of objects can be created and manipulated with SQL.
In Sql if we look at the structure we first have a database for individual user and inside that database we have multiple objects means tables we can refer to the table as object
For ex: Select * from dbo.student
dbo here is the Database Object which tells about the Schema we are using
Schema is like a container which contain objects or elements or tables whatever you want to say. So this container is like a class and everything inside this container is like an object