There are two kinds of subspace jumps. Short range, intra-system jumps can happen anywhere within a star system, but they can only go within the star system - they're linked to the gravity well if the star.
Intersystem jumps, I.e. Going from star system to star system, requires a subspace node, which is like one end of a tunnel. Jumping here can take you to a specific other node around a specific other star, but only that other node.
Post the end of FS1, the size of the ship involved doesn't really matter, since fighters on up can perform intersystem jumps, but the fighter scale drives remain more expensive to produce, so not every single fighter has them. At least an intrasystem drive is basically ubiquitous on fighters though.