In Camera Editing

What is it: 
The phrase 'In-camera editing' refers to the process of editing a sequence inside the camera
 after shooting by pausing the recording between shots at precise points so that no cutting is required afterwards. The cinematographer shoots the sequences in a certain way instead. So there is no editing after shooting because it would have already been done while shooting.
The whole process takes a lot of planning so that everything is in order and organised when it comes to shooting and presenting it.


Pros:
The technique is good because it reduces the cost of the production. When the cost of film was a significant fraction of the budget, film makes would use this technique to maximize the film usage.
Another thing is technique is good for will be saving time, even though you might take longer to plan the film, once you have finished shooting there is nothing else to do but present it.
This technique is also useful to those who's editing skills are not as good as their shooting skills.

Cons:
This technique involves a lot of multi tasking since you are doing two things at once

How to do it: 
In camera editing is not really editing at all, instead it refers to the process of shooting your film sequentially so that each shot is in order, and at whatever the length you finished shooting will be the length of your finished film.