Mean + gerund expresses what the result of an action will be, or what will be necessary. The word mean could be replaced by the word involve.
- If you take that job in London it will mean travelling for two hours every day.
- We could take the ferry to France, but that will mean spending a night in a hotel.
- Buying this jacket now means not buying another until next year.
- Leaving school would mean finding a job.
Mean + infinitive expresses an intention or a plan. The word mean could be replaced by the word intend.
- Did you mean to dial this number?
- I mean to finish this job by the end of the week!
- I didn't mean to hurt you.
- I meant to return the books on time.