How are away goals counted in football?

Answer 1

Generally away goals are counted like home goals.

Only in Play-Off like cup competitions they have an importance.

In Champions League in the aggregate rounds for example, the teams have one home game and one away game. If the addition of the goals over both teams is equal, the away goal counts.

For example:

Inter Milan won against Barcelona at home 3:1

If Barcelona had won their home game 2:0 against Inter, the addition is 3:3.

In this case Barcelona would have been in the next round, because they shoot a goal in Milan.

But Barcelona just won 1:0. The addition is 3:2 for Milan, so Milan reached the final.

If the score in Barcelona would be 3:1 for Barcelona, the addition would be 4:4 and the away goals are the same, then there would have been an Overtime.