What is 'inception' vs. stealing secrets?

Short answer

• Stealing secrets (often called extraction) = entering someone’s dream to find and take information they already have.
• Inception = deliberately planting an idea in someone’s subconscious so they accept it as their own.

How they differ (in the film’s terms)

• Goal: Extraction retrieves an existing memory or secret; inception creates a new internal motivation or belief.
• Difficulty: Extraction is risky but straightforward; inception is called “impossible” because the idea must feel organic to the target rather than imposed.
• Method: Inception requires a deeper, multi-layered plan — nested dream levels, heavy sedation, staged events and emotional triggers so the planted idea will take root naturally. The Cobb team’s mission is to plant an idea in Robert Fischer’s mind so he thinks it came from him.
• Stakes: Both carry risks (death in a dream can send you to limbo), but inception has extra ethical and psychological danger — Cobb’s backstory shows how a planted idea (the one he put in Mal) had devastating real-world consequences.

Bottom line Extraction is theft of what’s already there; inception is the subtler, harder act of manufacturing belief inside someone’s mind.