Wheelchair accessibility requires things like ramps and elevators instead of stairs, wide enough hallways and doorways, counters and cabinets that are low enough to reach from the chair, enough room next to toilets and access to sinks (which sometimes requires recessed or removing cabinets underneath to let the chair move forward).
Wheelchairs come in different styles and sizes. Many require manual pushing; some are motorized. They have different levels of support -- some are designed for people with control and strength in their upper bodies, while others provide support for those who also have disabilities affecting their ability to sit up or upper body strength. There are also motorized scooters and chairs.