Offline Video editing
used when you’re working with high file size/high resolution video files. The file size of raw (or uncompressed footage) can be astronomical and it will tax your computer system if it isn’t equipped to handle such a workload. By transcoding that footage down into a lower resolution format you can help speed up the editing process by a lot. Just be aware that while the editing process will go much smoother, you will lose time on the front-end and back-end because you will need to transcode and then eventually replace the lower resolution footage. Generally you don’t need to use offline editing if you have applications like Premiere Pro, Final Cut Pro X and Avid Media Composer can work perfectly with raw footage. All of which can work with raw footage with for the most part ease. With the advancements in computer technology the need for an offline edit is getting smaller. As film resolutions grew larger and the file sizes bigger, and transcoding was easier, editors would duplicate the footage but at a lower resolution in order to speed up the actual editing process. Learn more here.
Real Time Video Editing
Where real time video editing is mostly used in is genres like sports, events, coverage, and music, rare in fictional video such as drama, comedy, and others. Real time video editing can be very complicated especially when you only have one camera, its basically pointless to try to do so when this is the scenario however it is plausible in some cases. The most common way around this problem is to use multiple cameras. Sporting events often have a dozen or more cameras from different angles, meaning the director can always use the best shot, and cameras can re-position while they are not being used. Some music videos make a feature of using a single shot for the entire video. This can be very effective and generate a point of discussion. A variation of true real-time video is a serialized story such as a soap drama. Although each individual episode contains time-compressed story-telling, the series as a whole develops more-or-less in real time. A year in the series takes a year in real life to watch. In this way the viewer feels like they are following the lives of the characters. Learn more here.
There are various uses of offline and real time video editing, you have to look into which best interest you in your situation.