A block is four training weeks. With deload on, a fifth week follows with fewer sets and lighter weights so you recover before the next block.
What changes
Half the sets (rounded up), about 10% less weight, the bottom of the rep range and more reps left in reserve. The exercises stay the same.
Deload week: fewer sets and lighter weights to recover.
Afterwards
A deload week is never used to judge progress. The next block starts from your last normal week.
On or off
Deload is on by default for intermediate and advanced lifters and off for beginners. It is one of the answers the plan is built from: Plan settings shows it, and building a new plan changes it.
Write to support@joinrigor.com.