As to what is ratio decidendi has been succinctly explained by this Court in Regional Manager v. Pawan Kumar Dubey, (1976) 3 SCC 334.
“Indeed, we do not think, principles of law declared and applied so often have really changed. But, application of same law to differing circumstances and facts of various cases, which have come up to this Court, could create an impression sometimes, there is some conflict between different decisions of this Court. Even where there appears to be some conflict, it would, we think, vanish when ratio decidendi of each case is correctly understood. It is a rule deducible from application of law to facts and circumstances of a case which constitutes its ratio decidendi and not some conclusion based upon facts which may appear to be similar. One additional or different fact can make a world of difference between conclusions in two cases even when same principles are applied in each case to similar facts.”
– Hon’ble Justice B.R. Gavai, Dr. N. Karthikeyan v. State of Tamil Nadu, [Writ Petition (Civil) No. 53 of 2022].