What does 5G. Low band mean

5G uses different frequencies. 5G Low Band provides wider coverage, but at slower speeds. Higher frequencies provide faster signal speed, but not as much coverage.

In other words, everything is a trade off. You can have wider coverage, but speeds will slow. Or, you can have faster speeds, but the coverage will be significantly less.

The best compromise might be to use mid-band, if it is available.

Or you just use mid band.

"Spectrum in the 1 GHz - 6 GHz range is mid-band spectrum and it is considered ideal for 5G because it can carry plenty of data while also traveling significant distances."

https://www.nokia.com/thought-leadership/articles/spectrum-bands-5g-world/

This explains it pretty well: https://www.digitaltrends.com/mobile/what-is-low-band-5g-sub-6-explained/