Hi,
How do these relate and differ?
I see them Used with queries but cannot understand. I'm just starting JDBC. Sorry if it is noobish ;)

Well the api docs say

Executes the given SQL statement, which returns a single ResultSet object.

for executeQuery and

Executes the given SQL statement, which may be an INSERT, UPDATE, or DELETE statement or an SQL statement that returns nothing, such as an SQL DDL statement.

for executeUpdate