Google says about this:
There is a difference in meaning between “a little” and “little”.
The meaning of “a little” is positive. It means some or a small amount, such as, “I have a little money.”, “He made a little progress.”, etc.
On the other hand, “little” has a negativemeaning. It means an extremely small amount or an amount that is less than expected or wished for, as in, “I have little money.”, “He made little progress.”, etc.