The only real difference between almond oil and sweet almond oil is in the taste and how the almond oil is extracted.
The sweet almond oil has a bit better and sweeter taste than regular almond oil whereas the regular almond oil has a more bitter taste to it.
Sweet almond oil is more considered an essential oil while the regular almond oil is made from many other varieties of almonds and is not considered an almond oil.
The bitter almond oil is made from several different types of almonds but the regular sweet almond oil uses one kind of almond oil.