Oppostions

Oppositions have a meaning of conflict like squares, just more centered on balance. Unlike squares where the discord is happening within, this aspect typically manifests itself as a tension with the outside world. The two opposing planets need to be balanced/equalized to displace the pressure and achieve harmony. 

Too much to one side or the other will not allow a balance to happen. The difficulty with oppositions lies in the need to examine both sides of the conflict in order to figure out where the imbalance exists. Figuring this out means double the work, double the time, and double the effort which can be exasperating.

Oppositions usually occur within opposite signs and this can be a further indicator of the nature of a person with oppositions. For example, the Sun opposed the Moon in a chart instantly means the individual was born during a full moon and the qualities that inherently come with that aspect.

For more on aspects see here.