Comparison
Recommendation vs Validation
Recommendation is the system suggesting you; validation is the system confirming, against evidence, that you actually satisfy a requirement. A vendor can be recommended and then fail validation when the requirement is tested and the evidence is not there. Validation is where evidence strategy matters most.
What Recommendation is
Recommendation is your company being put forward as a candidate within an answer.
What Validation is
Validation is the stage where an evaluator checks whether a vendor credibly meets a requirement, using the evidence it can find.
Where they overlap
Both concern how an evaluator treats your company against a buyer's needs, and validation acts on the recommended set. Strong validation reinforces a recommendation.
Where they differ
Recommendation can rest on general relevance; validation demands specific evidence for a specific requirement. This is where a plausible-looking recommendation collapses if the proof an evaluator needs is missing.
Where both fit in the commercial evaluation lifecycle
Recommendation is the recommendation stage; validation is the validation stage that follows requirement evaluation. Validation is where the evidence gap decides whether a recommendation survives.