Seek and Records are timers that search the program guide and make recordings based on what criteria you put in to the search. So say you wanted to record everything that Matt Damon ever did, you can do a search and then hit Seek and Record to save all those programs. Or I use it to record a show that I know I want to record but isn't in the guide yet. Say "Game of Thrones" which doesn't start until April 1st. I just make sure to select "Only New" and restrict the search to channel 300 so that repeats on other channels won't get recorded.
DVR timers are created based on specific events in the guide. If you scroll in the guide to a show at a specific date and time and press the record button on the remote, that is a DVR timer.