Good & 100 % free Video Editor and Slicing Program easy to use.

Video Editor Softwares:  There are lots of video editor software available for free.  Some of them are available with open source that can be used for the various purpose you can easily download from any website such file hippo, Softonic etc.

Video Editors are used for editing videos such as slicing videos giving it effects, adjusting color contrast, shadow, and other many effects.

Some of them are as Da Vinci Resolve,  Microsoft Movie Maker, & iMovie these video editors can be used for video editing at a good level.

Microsoft Movie Maker is generally used by windows user & iMovie used by MacOS user. Here are is an example for Linux user. Linux user can install the best one i.e. Linux distros such as Artisx music Linux and so on.

You can also use Handbrake & Mkv Merge They all have a small learning curve both are free!

Yamb is another really good idea for video editing it is totally free video editor program.