Little means not much or hardly any. It always gives us negative idea of something used with uncountable noun.
There is little milk in the pot. (not much)
There is little salt in the jar. (not much to say)
There is little water in the bottle. (not much)
A little means a small amount of something gives positive idea.
I am a little faster.
Give me a little milk.
I have a little water to drink.
I know your brother a little.
The little means all in amount though it is not much.
He gave me the little food he had.
She helped the little she could do.
You did the little work you could do.
Use of Few, A few, The few
Few means not many and it gives us the negative sense.
I have few friends. (not many)
He had few relatives in this town.
I have few books.
You had few story books.
His father had few cars.
A few means some and it gives us the positive sense.
I have a few pens.
He had a few friends in his school life.
They have a few goats in their firm house.
I have a few books.
She has a few relatives in this town.
I know a few people here in this area.
The few means not more but all. It gives us positive sense.
I have given him the few books I had. (Though it means little in amount but all)
I have lost the few books I had.
He has read the few books he has.