표준 - well defined, academic or government standards officially accepted and used. 수준 - general lay term for a perceived or expected level of quality, trait, etc. So their usages tend to differ. 이 제품은 정부가 정한 한국 표준에 부합한다 => This product meets the Korean Standards(KS) as determined by the government. 표준시 => standard time, 표준어 => standard language, 표준형 => standard type 실력이 일정 수준에 이르면.. => if your skill reaches a certain level.. (수준 is just a "level" - a vague reference) 자기 수준에 맞게 살아야 한다 => We have to live by our means. 수준 높은 서비스를 제공합니다 => (We) provide high quality service. As you can see, 수준 is used more in a vague and subjective sense without a clear reference, while 표준 suggests an official standard.