There isnt any hard n fast rule...like LKO isnt Jn while CNB/SPN line branch-off just after LKO...controlled by LKO Signalling... While GKP/FD-SLN/PBH line branch off just b4 Dilkusha (although Dilkusha isnt any station bt acts as controlling point for this branch off)..bt still technically, its after LKO & b4 any other station where branching hppns....
One thing to consider is the signalling control at the point where multiple routes converge. There are some places where the point where routes separate is quite far from the nearest station, and basically the separation point falls outside the signalling territory of the station. In such cases, even though one can technically switch routes at the station, it'll not be officially termed as a Junction.
never knew this point :) in that case my point of PEN not being a junction has a valid explanation as the point of divergence is indeed out of signalling territory of station, almost 5 Kms away from main station.
dictionary meaning of Junction: a point where two or more things especiallyroads or railway lines meet or are joined. Samalya (Gujarat) is one such stations where lines are meeting and hence it is Junction.