What does the term sql outer join mean?

SQL is a special language for making queries to databases. An outer join is a special form of joining two tables within the database, when a SELECT query is made. In the outcome of the query you will find all selected entries from the so called "left table" (the table that was target of the select query) and only those entries from the "right table" (the one that is joined with the other) that fit a specified joining condition.