Productivity is a measure of output per unit of labur.
Most commonly used number is output in Pounds (or Dollar) per hour of work.
It answers the question :
What is the value of goods (or service) an average representative UK worker produces for an hour of work?
For UK, the answer in 2019 was abotu $54
For Germany, the answer was $69
So an average German worker produced over 25% more an hour than an average UK worker in 2019.
Or another way of looking at it is :
An average German worker produces in 4 days what an UK worker produces in 5 days. To achieve the same standard of living as UK, Germans need to work just 4 days a week (but obviously they work 5 days, hence higher standard of living!)
Ultimately, this number determines prosperity of nations, wages and standard of living, quality of public services and so on.
In your specific example, it would appear that your productivity at work fell due to poor decisions by your employer. If that happened to everyone else in the company, then the productivity of the business had fallen too.
Thankfully in the entire economy, something like that usually doesn't happen, and productivity normally rises over time - due to innovations, investment and improvement in skills. Obviously the experience of individual businesses will differ, some will fail, some will do well.