Vanessa Bryant says Kobe's charity will have a new name -- the Mamba & Mambacita Sports Foundation -- and she says it's all to honor Gianna Bryant.

"Because there is no #24 without #2, we have updated the Mamba Sports Foundation to now be called the Mamba & Mambacita Sports Foundation," Vanessa said Thursday.

It's an amazing tribute ... especially because Vanessa says the foundation's goal of helping young people through sports "remains the same -- and stronger than ever."

If you're unfamiliar ... Kobe's charity has helped more than 10,000 kids as well as hundreds of veterans -- with the org saying they have over 1,000 volunteers lending a hand.