Youtube is the most used video streaming site in the world. It is owned by Google. You can create videos and share them free of charge as long as you have the licenece to use all the content, including the soundtrack. You can choose to have adverts (for other products or services) displayed with your video. If your video is watched by a large numebr of people you can consider monetizing the video. You can collect your videos together into a youtube channel and also collate other videos that are relevant or that you like.
Men spend 44% more time watching Youtube videos thatn women. Video gaming videos are very popular with men, health and beauty videos for women. Half of Youtube users are over 35. Pets and animal videos are enjotyed by all.
Take great care with descriptions and tags for your video as these will affect how well your video is indexed and found. You must have uploaded at least 2 videos before they are indexed.
Youtube may link adverts and related videos to your channel or video that you consider inappropriate (or from a competitor). If you want more control you may want to consider Vimeo or Sprout to host your videos. If you are sharing a video on Facebook a direct upload to Facebook is more effective than a sharing a Youtube link.