Particularly in the context of the usage of "high definition" and "resolution", as in quality of digital sound, picture, and/or video. My question is spurred by my description of and under an image, where I say, "Links to higher resolution, original upload." I struggled with deciding which term to use.
Resolution is a technical term pertaining to the pixel count of an image, while definition has more to do with image clarity (seeing more details) - although in most cases they are used interchangeably in practice.
Assume you had a heavily compressed version of a screenshot, that was the same dimensions (say 1280x960) as the original but much smaller file size and also a corresponding loss in detail. This blurry version would be the same resolution but a lower definition than the original source.
In Hi-Def TVs, the increase in picture resolution enables output that has higher definition as well, hence the name.