Planetary Conjunctions

If more than one planet is in a house/sign, then they are all aspecting each other which is called a conjunction and influencing the house they are in and the house opposite.
You can also use their rulership too so if for a Taurus ascendant Jupiter is in Cancer with Mars, they are conjunct. You can say 8th and 11th House ruler Jupiter is aspecting Cancer the 3rd house as is Mars ruler of 7th and 12th house. As well as influencing each other and the house opposite to Cancer which is Capricorn the 9th house. You now put all these elements together one by one.
Now you can see how 2 planets conjunct can have a great deal of say in the house they are in and the opposite house, if say Moon and the Sun are conjunct in Capricorn. Then all 4 planets are influencing each other, the two signs/houses. The person will be most busy with those areas of their life (Cancer the 3rd house and Capricorn the 9th), This will be specially busy if Rahu is there as it magnifies the house it sit in as does Jupiter due to its expanding nature.
I use Sidereal zodiac.