【Task】 , 【duty】 ,  【assignment】 ,  【job】 ,  【stint】 ,  【chore】  are comparable when they mean a piece of work which one is asked to do and is expected to accomplish.

【Task】 refers to a specific piece of work or service usually imposed by authority or circumstance but sometimes undertaken voluntarily.

【Duty】 is likely to indicate work, service, or conduct enjoined on a person because of his rank, status, occupation, or affiliation; it is more likely in most uses to suggest obligation, often moral, than specific imposition by a taskmaster.

【Assignment】 suggests a specific amount of work or sort of service assigned authoritatively.

【Job】 is a general term wide in suggestion ranging from voluntary undertaking of some signal service down to an assigned bit of menial work.

【Stint】 stresses carefully or equitably measured or timed apportionment of work.

【Chore】 is likely to suggest minor routine activity necessary for continuing satisfactory operating (as of farm or office).