The Latin phrase omnia vincit amor expresses the idea that love has the power to overcome all obstacles or difficulties. It literally means that "love conquers all!"
The phrase comes from the Roman poet Virgil, who used it in Eclogues, written around 38 BCE. In the poem, the character Gallus is in love, but his love is not returned. He eventually concludes that there is no remedy for his feelings, as love conquers all, and it must be yielded to. Breaking down the phrase, omnia means "all things"; vincit means "conquers" or "overcomes"; and amor means "love." That seems backwards when translated to English, so sometimes you'll see it as amor vincit omnia.