The classic, what kind of isomer do I have here flowchart. There are a number of these online but it is useful. Surprisingly, hard to fit onto one page (nicely).

The shape of molecules is vital to understanding their chemistry and properties. The simple geometry of each atom is only half the picture, and you must also consider stereoisomers. These are compounds that have all the same atoms and bonds yet are different due to their shape. Students often find this a daunting topic. This introduction just lays out the basics. Sometime in the future, I’ll go into more detail (as I do teach a postgraduate course on this topic!)