Every substance in the Carbonchemistry has a main name, based on the number of C-atoms in the main chain:

Met..., et..., prop..., but..., pent..., hex..., hept..., oct..., non..., dec..., in general: alk...
on the dots appear suffixes:
  1. ane: the main chain has only single bonds.
  2. ene: the main chain has also double bonds.
  3. yne: the main chain has also triple bonds.
  4. yl: in this case we deal with a branch, not with a main chain.

Propene is a molecule with a chain of three C-atoms with one double bond.
The position of the double and triple bonds are indicated with numbers, if necessary.
3-ethyle is a branch of two C-atoms and connected to the third C of the main chain.

Besides suffixes, there are also prefixes:
  1. Mono, di, tri, tetra, penta, hexa, hepta, octa, nona, deca
    indicating 1 - 10 as also the number of a certain group.
  2. Cyclo
    then the main chain is not linear, but circular.