The words few and several are determiners. They both refer to a small quantity or number. There is a difference.
Few is pessimistic. It is used to stress the smallness of the quantity or number.
- Few people can understand philosophy. (Perhaps one or two people can understand it. Note that here the emphasis is on the smallness of the number.)
- Few politicians are honest. (Perhaps one or two are honest but the vast majority of them are corrupt.)
Several also refers to a small number, but it is more optimistic.
- Few children participated in the event. (Perhaps one or two)
- Several children participated in the event. (Not many but certainly more than a few)
- The movie won a few awards. (Only a few awards, not enough to be proud of)
- The movie won several awards. (More than a few, enough to be proud of)