The conditional layout plays a vital role in Zoho CRM. It manages dependency between fields in layouts You can have a look here.
For Instance: In The Lead information the particulars required for Interviewers may have a different dependency on the interview type-
Pre-interview form or a Post-interview form.
If you will Choose the Pre-interview form then it will show the form for only Pre-interview form Instead of both types of form. Then the structure of the form looks fine and this will create less space rather than more space.
Steps of layout rules:
Firstly Go to setup then Customization choose Modules and Fields
From the list of modules, select the required module. Select Leads Module
Go to the Layout rules then click New Layout Rule.