Where is the category/product stored?

Are they stored in database? Why I couldn't see them in my database tables?

And how the ID is generated? it seems category and product can have same ID.

Thanks.

Category and product can have the same id because they are separate things.

They are stored in tables - the product id is in the table "products," and the category id(s) for each product, is in the table products_to_categories. The categories themselves are stored in the table "categories." If you use phpMyAdmin to examine your database, you can look at all these tables.

swguy:

Category and product can have the same id because they are separate things.

They are stored in tables - the product id is in the table "products," and the category id(s) for each product, is in the table products_to_categories. The categories themselves are stored in the table "categories." If you use phpMyAdmin to examine your database, you can look at all these tables.

I looked in my database. I do have the catagories listed but do not have folder called "Products" The last folder in the list is "newsletter".
It seems the tables are listed alphabetically and stops t the N.

The site is working except for Special tabs no working..

Any clue what is happening with the database display?

I assume you are using phpmyadmin?
You are only looking at the first of 3 pages of tables.
Scroll to the top and click on the "next" page

gilby:

I assume you are using phpmyadmin?
You are only looking at the first of 3 pages of tables.
Scroll to the top and click on the "next" page

Gilby is correct - the list of tables is just being paginated. Your site would not work if it were missing the tables after Newsletter.