Used for a small number of countable objects, typically two to six. Common in both spoken and written Japanese.
There are several apples on the desk.
Please answer a few questions.
I bought several apples.
There are a few oranges in the box.
Please hand out a few pieces of candy to each participant.
いくつか is a general, counter-free way to say 'a few/several', while 数個 specifically uses the 個 counter for countable objects.
数枚 is used for a few flat objects like paper or plates, while 数個 is used for general countable objects.
数本 is used for a few long, cylindrical objects like bottles or pencils, while 数個 is used for general countable objects.
若干 is a more formal word for 'some/a small amount' that can apply to uncountable quantities too, while 数個 is limited to a few countable items.
数個 is concrete, used for counting a handful of physical objects, while 一二 is vaguer and often used for abstract quantities like time or people.
multiple items; several pieces; a number of things
Compound of 数 (sū, 'number') and 個 (ko, counter for small objects). The reading すうこ follows standard on'yomi.