2. A relation is in first normal form if it does not contain repeating groups.
A relation is in second normal form if it is in first normal form and no non-key attribute is dependent on only a portion of the primary key. (Note: an attribute is a non-key attribute if it is not a part of the primary key).
A relation is in third normal form if it is in second normal form and if the only determinants it contains are candidate keys. (Note: any attribute that determines another attribute is called a determinant).
and crs. In this case stucrs is a bridge table between them.

3. In a many to many relationship you cannot you need a bridge table
In a many to many relationship you cannot you need a bridge table. In this example, you cannot carry stars on the movie table because you would have repeating groups and you cannot carry movies on the star table because you would have repeating groups. A bridge table combines the movieid and the starid to make a bridge. The salary applies to both parts of the key. It is the salary for a particular movie and a particular stars role in that movie.

4. You can also see bridging between the tables
You can also see bridging between the tables. For example an for many items and an item is ordered many times.

5. Example of passing to a function and the function receiving.

6. An example of a function where nothing is sent.

7. sent and received for use.

8. Gathering information that will be processed in a PHP program
Gathering information that will be processed in a PHP program. I entered 2 in pounds and 11 in ounces for the test.

9. function as an alternative to passing and receiving.