Billiards is a game played on a table with no pockets. In korea, the tables are often 4 feet long and the game is played with 4 balls. Across Europe the standard table is 5x10 and is played with 3 balls. Various games can be played on these tables and all are point games. a point is usually scored by making your cue ball bounce off one ball and then contacting another ball on the table. there may restrictions about which ball needs to be hit, or how many rails must alos be hit, or the oder in which any of these happen. The most common game played today is called 3-Cushion billiards. to score a point in 3 cushion you must make your cue ball contact the other two balls on the table. However, before the cue ball comes in contact with the second of the two balls, it must hit (in any order), the other ball and at *least* three rails. it is a very hard game, as such American's have little patients for it. it is played through out Europe, Scandinavia, and Asia. it should also be noted that "pool" is not "billiards", however people often misuse the term 'billiards" to mean "pool".
I learned to play billiards when I was 10 years old, but still can't make more than 3 points in a row.