Much has been made about the stupid decision to translate instinkt and Trieb into the English word instinct. One of the main effects is this translation error is that it creates and maintains a misunderstanding of what drive is and what makes drive different from instincts.
[T]here is a relentless demand (exigence) that in Freud’s terms is called the drive. A demand that does not quench like thirst, which does not satisfy like hunger, an imperative, absolute demand, which cannot be expressed in words, but which is insatiable, always wants more, does not know limits or end of time.
Drive is the itch that itches more if you scratch it. It is the hunger that becomes worse if you eat. It is the thirst that becomes more persistent as you drink.
Also of interest along these lines is this line from No Subject:
Whereas instinct denotes a mythical pre-linguisticneed, the drive is completely removed from the realm of biology.
Instincts are things that are in the service of keeping the body alive by motivating the body to get its needs meet.
The drives differ from biological needs in that they can never be satisfied, and do not aim at an object but rather circle perpetually round it.
The drive will circle faster and faster, picking up speed until the rate of the orbit becomes too much. The effect of the drive going un-checked is subject burns out, disintegrates, and dies. The death of the subject is also the end of desire. The end of desire is death.
All drive is, in some way, the death drive.