[Colin F]

As you correctly interpreted, you are setting the columns in the ()'s
id... is one long command.

"id" is the name of the column
"tinyint" is the columntype (different types let you enter different types of data, some let you enter numbers (anything with *int), some let you enter text or text mixed with numbers, and so on)
(4) is the maximum length of the data entered in this column
DEFAULT'0' tells it to set this column to '0' if no data is entered (will be overriden by auto_increment)
auto_increment means it will assign a number automatically, starting with 1 and just always counting one up.
PRIMARY KEY and UNIQUE ID are indexes, which allow faster searching of the table, if only one of these values are searched for., UNIQUE ID additionally tells it that every entry into that column is unique

I missed some things, but maybe it helped you a bit. I'll try explain the rest when I have a bit more time.