A slide-in range is a cross between a drop-in and freestanding range. Like a freestanding range, it has a bottom drawer for storage (or possibly for a broiler compartment). Like a drop-in range, the sides are not paneled and it's designed to sit in between cabinetry.
Slide-in ranges will not have a control panel that extends upwards from the back of the range, instead it will have a control panel on the front above the oven door (for an example, see the photo above). This helps excentuate the slide-in's streamlined look. This style range can be especially useful in a kitchen island setting where you wouldn't a range panel that rises higher than the countertop.
Slide-ins close the gaps between the range and the countertop. Slide-in ranges usually have the same price as drop-in ranges with similar features, but are more expensive than freestanding ranges with comparable features.