What does the " +/- " symbol mean on the nba.com boxscores?

Theres a section on the boxscores on nba.com labled " +/- " For instance, it will have +2 or -14 in the columns. What does it mean?

What does the " +/- " symbol mean on the nba.com boxscores?nba mock drafts

player efficiency. its how much a player contributes to the team's success when he is on the court.

What does the " +/- " symbol mean on the nba.com boxscores?nba street ,nba teams

its the Lenovo +/- Stat shows the power of teamwork. It's a way of showing the best-engineered/best combination of players on the court...
It shows the power of teamwork. It's a way of showing the best-engineered/best combination of players on the court. The Lenovo Stat is a plus/minus statistic that looks at the point differential when players are both in and out of the game, to see how the team performs with various combinations. The Lenovo Stat can look at a variety of combinations including the best two player, three player and even five player combinations for each game.

lets say, a player enters the court and his team is trailing by ten points. then leaves the game when his team is trailing by 20 points, he will get minus ten (-10) in his "+/-". but if he leaves the court when his team leads by 10. that player will receive plus 20 (+20).

i think it is similar to that "+/-" stat in NHL where if a player scores a goal, the offensive players that are inside the ice rink will get plus 1, while the defensive players will get minus 1