chemistry/ biology molecule structure?

[M B]

how do you read a skeletal structure? i am so confused on this... here is a link to a picture of a skeletal structure. why are there just blank shapes....?
http://upload.wikimedia.org/wikipedia/commons/thumb/9/91/Escitalopram-skeletal.png/200px-Escitalopram-skeletal.png

[Beaker]

This is a very hard to describe question with an in depth answer that requires some knowledge in organic chemistry. The blank shapes represent carbon molecules bonding with each other. Every intersection of lines represents a carbon atom. The letters are other atoms F=Fluorine, etc. There are also hydrogen atoms that are not even included in the picture.

[Andrew H]

Each corner of the hexagons is a carbon. The double lines in the hexagons are double bonds. Each corner-carbon has implied bonds to as many hydrogens as it would take it complete the octet.