If you have just started using Qlik Sense then you may be confused about what exactly the difference between a dimension and measure is in Qlik Sense or Qlikview.
Any visualisation can be said to contain dimensions and measures.
A measure is a calculation. It is something you need to write an excel function like sum() or count() or an if statement for. If you find yourself copying a formula from excel into Qlik then you should likely be putting it into the Measures library. You may also call a Measure a KPI. A measure would usually be the height of a bar in a bar chart, or the value of a point on a line chart. The y axis. Common examples are ‘sales value’, ‘sales volume’, ‘total employees’.
A dimension is usually something you are trying to compare. Like you may be interested in seeing a bar chart by Country or Over Time. Typically there is no calculation required for a dimension. It is an existing field in your table. Other common examples of dimensions are Region, Employee name, monthyear, date, hour.
It is worth pointing out that sometimes you do need to put formulas in a dimension, but this is usually not the case. If you find yourself doing that, you probably need to examine your data model.