No.
Drafting and slipstreaming are indeed two terms for the same thing. That is when two or more cars ride along in a tight row, one behind another. This allows the cars behind to use less power (and less fuel) to go faster, because the lead car is doing all the work of splitting the block of air the cars are moving through. The rest behind are riding through the low-pressure area in the wake of the first car.
Drafting is why geese fly in a V formation. The inside wing on each goose is in effect drafting in the slipstream of the goose in front of it, so it doesn't have to work as hard. You will note that geese of change position in the V to even out the work on both wings, and the leader dropps back and is replaced frequently.
Slipstreaming is primarily a benefit to the cars behind. They use less fuel, allowing fewer pits, and also allowing them more horsepower in reserve for a given speed. That's how slingshot passing works - tha car behind starts accelerating at the very back edge of the lead car's wake, and uses that extra power reserve to move up through the low pressure area following the lead car. With the extra momentum gained by doing this, the second car is going much faster, and is able to overtake the lead car even after pulling out from behind and losing the drafting advantage.
However, drafting also benefits the lead car. One direct way is called bump drafting, where the car behind actually pushes the car ahead (especially if it is faster, but not quite fast enough to overtake). The other way is less direct. Behind each fast-moving car is an area of low-pressure air caused by the displacement of the air the car is moving through. This low-pressure area acts like a vacuum, and actually sucks on the rear surfaces of the car, slowing it down. Having a car drafting behind eliminates or reduces this vacuum, allowing the lead car to travel faster as part of a train that it could alone.