Difference between Nearest neighbour and Reverse Nearest Neighbour query

Question

I am a little confused between the difference between Nearest and Reverse nearest neighbour queries.

Source : http://users.dcc.uchile.cl/~bebustos/cursos/2010/cc5202/papers/RKV95%20Nearest%20neighbor%20queries.pdf

"A user may point to a specific location or an object on the screen, and request the system to find the five nearest objects to it in the database."

Source : http://users.monash.edu.au/~aamirc/thesis/node22.html

A two-dimensional RNN query may ask the set of customers affected by the opening of a new store outlet location in order to inform the relevant customers. This query can also be used to identify the location which maximizes the number of potential customers.

Isnt the theme same? We have a point 'p' and we want to find some nearby objects to the query point?

I did some reading from the internet and still could not figure it out.

Answer 1

Found a great answer to this question. Summary of the answer : The nearest neighbour and reverse nearest neighbour are not symmetric.

Reference http://graphics.stanford.edu/courses/cs468-06-fall/Papers/19%20reverse%202.pdf