Graphic Design Terms 15-16: Point Size vs Pixel Size

When I first started in the typesetting and desktop publishing business we talked in picas and points and all ads were created using these units of measurement to specify size and placement of individual elements. As I moved onto creating graphics and enhancing photos in Photoshop, I learned about pixels. But what is the difference between point size and pixel size?
Point size is a unit of measurement used for fonts. Pixel size on the other hand, is a unit of measurement used for images. Pixel size is also used to measure screen widths and heights on any device on which images and videos are viewed or printed.
A point is the smallest size in a font and, in digital desktop publishing, it equates to 1/72 of an international inch. One point, or 1 pt, is 1/12 of a pica, and there are 12 picas to an inch. Thus, when I was coding ads in the early days of my career (see my post on My journey to becoming a graphic designer), I learned how to accurately measure both the height and width of ads and position individual elements in picas and points, a much finer unit than regular inch increments (sixteenths).
A pixel refers to the smallest point (or dot) in a raster image (photo, jpg, png etc.), as well as videos, since they are graphics based. Each pixel is a sample of the image. The size of the actual pixel depends on the number of samples per inch and the device on which it is viewed and/or printed. The more samples, or pixels, per inch the smaller and finer the sample, thus the better quality the image.
PS: I had a really busy week with clients and other business operations last week so I’m a bit behind on my blog and do not have time to create or find graphics to accompany this post.