Answer
save replaces an entire document if it exists or inserts it if not. update modifies only specified fields using update operators.
Quick Answer
save() was removed in MongoDB 5.x. Previously: if the document had an _id that matched an existing document, it replaced the whole document; otherwise it inserted. update() (now updateOne/updateMany) modifies specific fields. Always use insertOne/updateOne/replaceOne explicitly - they're clearer about intent and safer than the old save() which could silently replace entire documents.
S
SugharaIQ Editorial Team
Verified Answer
This answer has been peer-reviewed by industry experts holding senior engineering roles to ensure technical accuracy and relevance for modern interview standards.
Want to bookmark, take notes, or join discussions?
Sign in to access all features and personalize your learning experience.
Source: SugharaIQ