NTES is the salt of Railfanning. IRI is the sugar. - Kirti Solanki

Howrah is just like Lucknow Jn NER.
Just a simple explanation.
Junction is a point where a number of train comes and gets divert to no. protruding line, in both of the above cases the tracks are originating from station and trains moves after reversal at Howrah.Take example of MTJ-CPR Express at LJN and CNB-KGM Garib Rath Express at LJN,both getting reversal at LJN.
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is diverted on BBK-FD section and other to HRI-BE section.
Similarly is HWH take example Kunchenjunga Express.
You see there is no factor involved for being a junction.

No other train reverses and move to different lines from LTT or BDTS,only trains originates and end here.
Now Kalyan is a junction,trains can move to Karjat or Kasara lines.

Both are quite dissimilar actually.
Lucknow Junction is a carryover from the pre-independence time when a single station used to cater to both MG and BG at Lucknow, owned by the Oudh & Rohilkund railway. This was the original Lucknow Junction station. After independence, the MG portion of the station was given over to NER and the BG portion to NR. NER did not rename the station and retained the name as Lucknow Junction, while the NR station has, in time, been renamed to Lucknow Charbagh.
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Howrah on the other hand is not a junction by any means. A Junction needs either at least 3 different routes with through traffic, or alternatively, only 2 routes of different gauges so that through traffic is not possible. And other than NTES, Howrah station is not referred to as a junction anywhere else. RBS, SER and ER's official maps, all of them list it as just HWH station, showing a different Howrah Junction cabin which does the controlling.
Parli Vaijnath on the VKB-PBN route is also similar to HWH station in that it is a terminus station and all passing trains have to reverse there. However, it is not called a junction. There is only one route here, it's just that the station has a different layout. Coonoor (ONR) and Kurseong are also similar stations where every passing train needs a reversal. But there are no different routes to take after these stations. The trains continue along the same route. It is just the station having a different layout and thus they are not junctions.