Let's 1st understand what these planets represent on their own?

Jupiter - It is the most benefic planet and it represents all the auspicious things like Knowledge, Wisdom, Law, Guru, Spirituality, Religion, Philosophy, Literature, Elderly People and Children etc. For a girl, Jupiter also represents Husband.

Venus - Venus is Beauty, Desire and Love, Liquid Money. Venus is the main significator of marriage. Venus represents girlfriend or wife for a man. Venus is the significator of all relations, may it be husband-wife or mother-daughter. Philosophically speaking, Venus is also the cause of all the sufferings in our life. How? Because Venus represents our desires and we get pain and suffering in our life only when our desires are not fulfilled.

House Ruler - Besides these karaka things, Jupiter & Venus will also rule some houses in your chart and will represent things related to that house. Of course we can't cover conjunctions Ascendant and house wise else it will never be over. So, you have to include those things at the time of interpreting this conjunction. Also, we need to keep in mind all Yogas and Raj-Yogas which their conjunction would be making to completely understand the conjunction. Here, we can only cover meaning as per karakas. 

Meaning of Jupiter-Venus Conjunction - This can be seen as one of the most beneficial & auspicious conjunction as these two are most benefic planets in Astrology. 1st of all this person can be seen as a very rich person as Jupiter-Venus both represent Wealth but wealth/richness here should not be analysed in terms of money but it should be seen as richness of things related to the house/sign where these 2 planets are conjunct. Like in 2nd house/Taurus of Wealth, it can make a person really wealthy but if conjunction is in 9th house/Sagittarius of Higher Education, person can be rich with knowledge. But otherwise also, even karaka-wise both represent Wealth, so person can be very wealthy in this scenario. Jupiter-Venus both are Brahmin by Caste and represent Teachers, so this person can be high on knowledge and little preachy. It is also necessary for these people to share their knowledge to grow in life. Knowledge will be again regarding the house/sign they sit in. Like, in 2nd house/Taurus person can have knowledge of wealth & finance but in 8th house/Scorpio, they can be in knowledge of Occult/Mysticism. Jupiter expands the wealth, convenience, beauty and luxury factors of Venus, hence person can love a luxurious life and can be very good looking. Likewise, Venus adds factor of Convenience to Jupiter, that means person may love to learn and teach/preach others. They are also very creative by nature. This conjunction can give expansion of desires in matters of relations and relations can suffer. 

Who will win the Conjunction? - Jupiter will. Although both are benefic planets but by the fact of it huge size, Jupiter will at any day take over gentle Venus. 

Dignity & Strength - 

This conjunction works best in Pisces, where Venus is exalted and Jupiter is in own sign. 

In Taurus, Gemini, Libra, Capricorn & Aquarius, Venus will be strong as it is either in own signs or friendly signs. Hence, Jupiter will expand Venus qualities of desires and luxurious living. 

In Aries, Cancer, Leo, Scorpio & Sagittarius, Jupiter is in better dignity of being in own/exalted/friendly sign, so Venus will take supportive role and person will love to teach and preach his knowledge. 

In Virgo, both are weak, but it can create someone who isvery good at accounts, finance, stocks and share market.