Different ways to draw organic molecules include:

1.  Kekulé (straight-line)
2.  Condensed Formulas and
3. Bond-Line Formulas (zig-zag).

 The majority of the drawing is Bond-line (zig-zag) formula, but the -CH3 are written as condensed formulas, and the -OH group is written in Kekule form.

A widely used way of showing the 3D structure of molecules is the use of dashes, wedges, and straight lines. This drawing method is essential because the placement of different atoms could yield different molecules even if the molecular formulas were exactly the same. Below are two drawings of a 4-carbon molecule with two chlorines and two bromines attached.

Both drawings look like they represent the same molecule; however, if we add dashes and wedged we will see that two different molecules could be depicted:

An easier way to compare the two molecules is to rotate one of the bonds (here, it is the bond on the right):

Kekule structures are similar to Lewis Structures, but instead of covalent bonds being represented by electron dots, the two shared electrons are shown by a line.