This type of statement is called a query.
Selection is an operation in relational algebra that selects specified rows from a relation.
Single quotes are required around the string value being compared in the JOB column. Only those rows in the table in which the value in the JOB column matches precisely the spelling and case of the string you place in quotes will be returned. The default for the sort is ascending order. In the school environment you will be working with relatively small tables and your queries will not affect efficiency to a great degree. You also risk losing the index path on the specified columns.