Lazarus was an individual who was one of two "characters" in Jesus' parable of the Rich Man and Lazarus. This Lazarus was completely different than the brother of Mary and Martha, who lived in Bethany. Not much is told about him, except that he was a beggar living near the gate of a certain wealthy man. He was also afflicted, as it is described that "even the dogs came and licked his sores." 
It is not known whether or not the man was real or fictional, while this is explored further in the "Legacy" section for the purposes of the article he is treated as real.
There came a time when both Lazarus and the rich man died. The rich man received a burial, which could be perceived as what was optimal for that person, while there is no mention of a burial for Lazarus, who is rather "carried up" to heaven to Abraham's side. The rich man later looks up to see Abraham and Lazarus, and asks him to get Lazarus to dip his finger in water to help cool his tongue, something which leads Abraham to describe how there is no way that will happen, and a plea from the rich man to return from Hell and tell his brothers how bad it is. Such a plea at first sounds reasonable, but Abraham responds by telling him that even if he were to rise (or anyone for that matter) and tell them, they will not respond favorably since they "do not already listen to Moses and the laws of the prophets." Having no reference to him as a believer, Lazarus was shown compassion on by the Lord as a man who wasn't really given any thought while alive on Earth, and though he is not deemed as "faithful" in the parable, it can be assumed that he desired something more than the life he lived at the door of an incredibly wealthy individual.
Due to his hard life, he serves as an example for how God will take in the poor and needy who live in agony, but will set apart himself and them from those who live pleasant and affluent lifestyles with little regard for even those at their doorstep. Jesus uses his life's example to help illustrate how a hard, stricken life may be ended by being with the faithful in Heaven.