The route reflector, as described in RFC 4456, is a router allowed to advertise (reflect) iBGP learned routes to other

BGP 4.26.2F Route Reflector Cluster

Route reflectors are commonly used to distribute routes between BGP peers belonging to the same autonomous system. However, this can lead to non-optimal path selection. The reason for this is that the route reflector chooses the optimal route based on IGP cost from its perspective. This may not be optimal from the perspective of the client as its location may be different from the RR