SpaceX's Dragon capsule has reached the hold point near the International Space Station, just 30m from the orbiting platform, and waiting for the optimum time for the station to grapple it in. It's taken several hours of testing and positioning to get Dragon in so close, with NASA and the SpaceX ground team repeatedly running through the "retreat" procedure which will halt the craft and back it away from the ISS should an issue arise.
NASA and SpaceX are now waiting for 7:40am ET, which is the next expected grapple point. The process must take place during a daylight pass, to give the crew aboard the ISS the best chance of snaring Dragon and bringing it in.
Now in calculation is the exact time when the final approach should begin, which will bring Dragon within 10m of the ISS and to the point where grappling can be attempted. It will then take several more hours of positioning and testing before the final docking process is completed and the two craft are docked.
The grappling process itself actually uses the ISS' robotic arm, using a combination of LIDAR (Light Detection And Ranging) and other sensors to guide it in. You can watch the whole process in the video below: