Accomplishing things. Getting work done. Whether it's work done for survival, something more abstract like your desk job, or personal goals like chores around the house or hobbies.
It is a measure of how your actions get you closer to your goals.
Hence, if my goal is learning Japanese, and I spend time in reading raw manga, I can argue I'm being productive. However, if my goal is to learn Rust, then reading raw manga is not being productive.
Productivity does not have an end goal other than what you set for yourself.
EDIT:
Edited the last sentence to make it say what I meant it to say. "Productivity has an end goal…" isn't it. 😅
Productivity is a measure of output completed whithin a time frame. This could be goods, services, or even personal goals as long as the output is measurable in some way and it was completed within a realistic time frame.
Washing dishes, losing weight, and making children happy can all be counted as productive if there are goals and a way to measure them. Even reduced anxiety by taking s day off could be described as productive if there is a way to measure it even if the measure is subjective. Cleaning up a park can be productive even though the end result is removing things instead of creating them!
Basically it is getting things done within a reasonable time frame and is not limited to business.
What you can accomplish given a fixed set of resources. Not to be confused with efficiency, which is how much those resources can accomplish in a given amount of time.
Productivity is simply a measure of what is produced.
American culture usually measures this as what gets done (work, chores and errands, creation of things, etc). I think that this is sort sighted. It can be productive to rest and instead produce energy in order to do other things later.
For my life? Productivity I would measure as what gets done in a certain time period. Some days I get a lot done, work and exercise and cook and garden - high productivity days. Other days I do less and rest, unproductive days. That's balanced.
For an economy? Production/number of employees. That's the # that keeps increasing here while real earnings/employee decreases.
Productivity is part of the dominant theology of (at least) Western culture and functionally extends and replaces the societal functions of christian (also other religions) conservatism to centralize power in a rigid and defensive structure of guilt and judgement.