What is bridge and lookup tables?
Thanks in advance
A bridge table is used for solving many to many relationships.
(Classis example is the one of students following classes; 1 student may attend more than 1 class and each class is attended by 1 or more students)
A lookup table is used for - example - looking up a description for a code.
The tables are often reused again and again in a model in different contexts (and aliased in the physical model to enable valid SQL)