Board Software
Gigabyte has a somewhat universal access hub for all of its programs. After downloading the program, you can install system drivers and Gigabyte's supporting software. My only complaint is when viewing the available software—Norton Internet Security is already checked off and will install if you aren't looking for it. Having Gigabyte-created software listed as suggested or "necessary" for download is fine, but auto-checked anti-virus or internet security software crosses into bloatware territory.
Gigabyte Easy Tune is the software for controlling CPU overclocking and voltage settings inside Windows. It is similar to Intel Extreme Tuning Utility, but designed solely for Gigabyte motherboards.
Gigabyte RGB Fusion 2.0 should be installed if one wants control over the RGB lighting. There are open-source alternatives, but those are not Gigabyte-branded and may not work as intended.
The Z690 AORUS Tachyon has overclocking software that isn't on the product page. In fact, it isn't supported officially, just like the XOC BIOS. Good news is that if you know where to look on the internet, it can be a helpful tool for precision overclocking inside Windows.