Below is explanation of how to split videos into parts on mac easily.
You can use Imovie.
iMovie has already been on your Mac, so you do not need to download it. This tool can help you:
Browse and share films.
Enjoy all your films inside the full screen Video browser.
Easily share a portion of a clip.
Make Hollywood-type trailers.
Pick from 14 trailer themes with spectacular graphics and authentic ratings by several of the world’s top film composers.
Customize movie business credits, cast labels, and logos.
File video on your trailer right in iMovie.
Build stunning movies.
How to split videos into parts on mac easily with iMovie
Use 3D Effect on iPhone 6s to rapidly start a new undertaking from your Home Screen.
Select from 8 unique subjects with music and transitions.
Boost your movie with slow motion, fast-forward, picture-in-picture, and split screen effects.
Produce A soundtrack using built in audio and sound files, songs out of your music collection, as well as your narration.
Use the iMovie extension to boost videos right within the Photos software.
Share your finished clip to iMovie Movie watching them with iCloud, including Apple TV***** on your entire devices.
Send films with Email and Messages.
Save videos and iMovie project files to iCloud Drive.
Project and Share movies files with AirDrop.
Use AirPlay to wirelessly stream movie.