Maybe you don't want to share your videos on social networks, or you want to send it to your parents, or you're trying to move that video from a trip from one device to another. You have a couple of options to send a large video file without worrying about it being compressed (like in email).
Online Cloud Services
These are free services that allow you to upload files to the cloud, then send a link to someone. Dropbox, iCloud Drive, and Google Drive are the largest players in the space. Just copy and paste the share link in an email or message and send it to anyone with whom you want to share the video. These services also have mobile apps that you can install and allow you to download/upload files with ease.
File Sharing Websites
Many free file transfer sites allow you to upload a single file and send it to different email addresses or create a share link to that file. We use WeTransfer and enjoy it because it doesn't require creating an account.
AirDrop
This technology allows you to share content with other Apple devices nearby. Perfect if you're trying to transfer a video from your iPhone to your Mac. Super easy and fast. Simply turn on AirDrop in your notification center and make sure to share with your contacts. From there, go to your Photos app to share whichever videos you want to.
If you'd like to learn more about AirDrop, please visit Apple's article here.