Regular quests - Those are just regular quests that RS gold tell a short story and are not connected or connected to any other quest. Quest series They are quite common in RuneScape because many quests tie to each other. They are tied together by the same story line and the same characters and usually they are a requirement to begin another.
There are occasions when the same quest can be connected to many others simultaneously, which will all come to an end in the quest. The majority of those quests revolve around one large area or continent. Completing your quest opens doors for the wider area.
Subquests are element of a larger quest. They may reward players with additional quest points and rewards. Subquests tend to be smaller and don't have additional requirements other than those in this main story. Miniquests are cheap OSRS gold short stories that can be utilized by Jagex to connect tales from other quests or even as standalone missions.