In which order pseudo-classes must be applied to <a> elements?

The order is this one:

1. :link
2. :visited
3. :focus
4. :hover
5. :active

Doing so in this way will prevent accidental overrides of styles on states.

We can use the "LoVe For Hairy Animals" as a mnemonic tool to remember the LVFHA order.

The :hover and :focus states usually have the same style because they are very similar in behaviour.