To reach the section called "Conditional formatting", right-click on a column header in the overview in the "Client", see 1 in the picture. Then go to the menu called "Conditional formatting", see 2 in the picture.
The reason for this extra coverage of "Conditional Formatting" in the docuemntation is because it is used in the special function "305 Color-coded planned work orders" which you can read more about here . In general this is used to make it easier to highlight interesting individual cells or multiple cells in different ways.
How this happens depends on what conditions are used but the result can be different visual aids such as using different colors, fonts, data bars and more.
To make it easier to find the information you are looking for each section will have its own documentation. You can find links to each section below.
Highlight
Cell Rules
Unique/Duplicate
Rules
Clear
Rules
Manage
Rules