There is a lot of buzz about the new song from The Weeknd and Future called "Low Life" that just popped up this Christmas. And with good reason — this is a solid piece of music that will definitely get you into the holiday spirit.
A low-life is someone who is considered by the community to be a bad person. It includes criminals, people of poor moral character and people who abuse the free gift of life that we all enjoy.
The lyrics of the song detail all kinds of bad behavior that is considered a part of a low life: drugs, alcohol, strippers, cheating, murder and spending excessive amounts of money. The lyrics are a bit heavy on the disapproval and a play on the word high life, but the song also demonstrates how easy it is to live a low life if you don't care about how others perceive your actions.
A person who is repping for that low life is usually representing their hometown in some way, either for good or bad. Typically this is done through the act of being a gang member, or other similar activities.
It is not a very polite term, but it has its uses in society. You may see it on TV if a low-life is being charged with a crime, or in the press when something bad happens to someone who is considered to be a low-life.