The (1) indicates this is the second time a file with this name was saved to the same location. You may want to check your original 720.mp4 file to see if they are identical or different parts of a series.
The filename is a generic name typically generated by web browsers or download managers when a file named "720.mp4" already exists in your downloads folder. The "720" likely refers to the 720p HD resolution ( pixels) of the video. 720(1).mp4
In specific archival contexts, such as the Hard Zone MTV Russia collection on Internet Archive , this specific naming convention is used to organize full episodes of televised broadcasts. Recommended Descriptive Labels The (1) indicates this is the second time
720p is considered "Standard HD." It strikes a balance between visual quality and smaller file sizes, making it ideal for mobile viewing or older hardware. The "720" likely refers to the 720p HD