Organizations of every size and representing every industry are always looking for ways to improve & drive performance. OKR tools are a widely accepted practice to set organizational, departmental and individual goals to plan where you want to go.
“OKRs'' simply mean “Objectives and Key Results”. The Objective is the aspirational goal whereas the Key Results are the important metrics that help you measure progress and the target metric you are aiming for within the period the OKRs are active (typically quarterly or annual).
A KPI (Key performance indicator) is basically a metric which helps determine progress. The OKR framework adds more structure around just these metrics. The Objective is the aspirational goal to inspire and show people the art of the possible. The Key Results are a series of metrics (or KPIs) which will help you measure the progress needed to achieve that Objective.
At the check-in you should assign a score out between 0 and 1 or use a % benchmark for KR. If you are using an OKR tool like Witsmate then you should update any comments about current status so others have more context about the score you have given. For Team/organizational OKRs you need to do check-ins as a group so that all contributors agree with the check-in.