Variables

When you reference parts of a pattern or a query, you do so by naming them. The names you give the different parts are called variables.

In this example:

MATCH (n)-->(b)
RETURN b

The variables are n and b.

Information regarding the naming of variables may be found here.

Variables are only visible in the same query part

Variables are not carried over to subsequent queries. If multiple query parts are chained together using WITH, variables have to be listed in the WITH clause to be carried over to the next part. For more information see WITH.