Videos and images can be altered to mislead and misinform the public, just like text-based sources can. Unfortunately, social media has proliferated this trend as many people fall for these dubious pieces of media.
"Deepfakes are doctored videos that use artificial intelligence technology to make a seemingly real video of something that didn't really happen." - Donna Mignardi and Jennifer Sturge, Calvert County Public Schools, Prince Frederick, Md.
Some tactics deepfake videos use:
Seeing Isn't Believing - Washington Post guide to manipulated video
Is That Video Real? - CNN explains how to spot fake videos
You can use certain search engines to do what is called a 'reverse image search'. This is when you search by copy/pasting or uploading a preexisting image. This is a good research strategy if you have an image that you think may have been altered or cropped to exclude information.
After you search by image, you will find:
If you click on 'news' or 'all', instead of staying in images:
You can see the dates of each webpage and when the image was posted. This can help you better understand where the image originated from, and to compare it from an earlier date to see if it has changed.