Understanding 2 Left Joins in same query

When using 2 Left Joins in the same query does the second Left Join work with the results from the first Left Join or with the table? For example:

SELECT firstName, LastName, Social, Birthplace
FROM Employee
LEFT JOIN ON Birthdays

Does the last LEFT JOIN use the results from the first Left JOIN or not?

Not if it is joined to something from the Employee table, which should be the case here.