The more detailed versions of the guidelines matter if you want more than just a basic TV signal: If you play video games at more than 30 frames per second, for example, or you intend to make full use of an HDR TV, or you want an HDMI cable that can also carry data over ethernet (most people do not, but that bandwidth can be used for other things).
For these types of scenarios, you must take refresh rate (measured in cycles per second, stated as Hertz, and abbreviated as Hz), the level of color precision (aka color depth, measured in bits; e.g., 8-bit, 10-bit, or 12-bit), and color data compression (i.e., chroma subsampling) into consideration. The higher you go with refresh rate and bit depth—and the less color data compression you opt for—the more data that will be pushed to your TV.