editing_non-linear/linear editing

Linear video editing (tape to tape) is a video editing post-production of selecting, arranging, and modifying images and sounds in a predetermined, ordered sequence. The only thing you need to take care is the order of editing; you can't go back and forth and edit. You have follow your storyboard and go chronologically. It was the original video tape editing method, before non-linear editing computers became available in the 1990s. These days, many people consider linear editing to be obsolete. This is not actually true. Although non-linear editing is the preferred method for most projects, linear editing still has a place. 

It is simple and inexpensive. There are very few complications with formats, hardware conflicts, etc. For some jobs linear editing is better. For example, if all you want to do is add two sections of video together, it is a lot quicker and easier to edit tape-to-tape than to capture and edit on a hard drive. Learning linear editing skills increases your knowledge base and versatility. According to many professional editors, those who learn linear editing first tend to become better all-round editors.

Non-linear editing completely changes the rules . Instead of building a program in sequence one shot at a time, non-linear systems let you work on any part of a program at any time. Changes that may take hours or even days on a linear system may take nothing more than a few mouse clicks with non-linear. Where linear editing makes you wait for tapes to cue up, non-linear gives you instant access to whatever clip you want, whenever you want it. By transferring the video from raw footage tapes onto hard disks inside a computer. Once inside the computer, the possibilities for manipulating the video literally become endless. 

Non-linear editing differs from linear editing in several fundamental ways: 
_first, video from the field tapes (or whatever the source is) is recorded to the editing computer's hard drive or RAID array prior to the edit session.
_next, rather than laying video to the recorder in sequential shots, the segments are assembled using a video-editing software program like Adobe Premier or Macromedia Director. The segments can be moved around at will in a drag-and-drop fashion.
_transitions (such as dissolves or wipes) can be placed between the segments. Also, most of these programs have some sort of CG or character generator feature built in for lower-thirds or titles.
_the work-in-progress can be viewed at any time during the edit in real time. Once the edit is complete, it is finally laid to video.
_non-linear video editing removes the need to lay down video in real time. It also allows the individual doing the editing to make changes at any point without affecting the rest of the edit.