Combining video files in Manjaro

How do you make combined file? I.E. Video 1 plus Video 2 equals Video 3

In the past I have used AVIDemux to combine videos, what video editing apps have you used or tried?

Sounds like you want to do this in a terminal,
$ ffmpeg -f concat -i videos.txt -c copy output8.mp4
Where videos.txt contains the name of the files you want to combine.
Note that this only works if they have the same codec. Otherwise I’d suggest kdenlive. Search for a tutorial and you will find it pretty easy to do.

Haven’t used that program. I will try it out. Thank you for input.

Not sure about your example. basically I want to combine two files into one new file:
blue.mp4 plus yellow.mp4 equals green.mp4…

I will try as per your example
Thank you for your input.

Video editors are usually good for that.
https://wiki.archlinux.org/title/List_of_applications/Multimedia#Video_editors