A reverse diet means raising your calories in small steps over several weeks after a diet ends, instead of jumping straight to maintenance. The hope is to "rev up" your metabolism again and slow fat regain after the diet.
It is not the same as a diet break or a refeed. Both happen in the middle of a diet, and the deficit continues afterwards. A reverse diet starts once the diet is over.
The evidence
Of the three strategies, the reverse diet has the thinnest evidence. A review on metabolic adaptation in athletes (Trexler et al. 2014) notes that reverse dieting became popular mainly through anecdotal reports and that research is needed to test whether it works. Controlled studies directly comparing a reverse diet with a straight switch to maintenance are hard to find.
That does not make a gradual increase wrong. It is a cautious way to find your maintenance. Just do not expect a proven metabolic bonus beyond that.
The simpler alternative
After a cut, you can also go straight to your estimated maintenance calories and then adjust by your trend. In the first few days the scale jumps as glycogen and water refill. That is normal and not fat.
What matters is what the trend does afterwards. If it keeps rising for two to three weeks, your maintenance estimate is too high and you trim a little. If it stays flat, you have found your maintenance. Whether you approach it slowly or in one step comes down more to how you handle hunger and control than to your metabolism.