Point to point The point to point method allows you to measure the distance between two points, which you can freely choose by clicking on the visualisation. A rectangle containing a diagonal line gets drawn with an adjusting length info beside it. You can use the freehand or the polyline option, which grant you greater freedom while measuring. The Polyline option allows you to add any number of lines at the endpoint of the previous line. Please note that the distance displayed beside the line is always the distance of the current polyline, for a sum of all the distances see the dialog under "diagonal".
Object to object The object to object method measures the shortest distance between two objects by clicking on them. A third click resets the previous selection and starts a new one. A popular use case would be verifying, if the required minimal distances have been met, so components can be mechanically placed without production problems.
Center to center The center to center method measures from the center of one object to the center of the second selected object, which is predominantly used to determine the so-called "pitches" of components.
Annular Ring In theory, the annular ring method can be used on every two overlapping objects, in practice, however, it is intended for drill holes measuring, if a hole is within the bounds of a copper pad while also adhering to the tolerance range for possible discrepancies in production. To use the annular ring method, you have to activate at least two layers, e.g. your top and drill layer and click on the area they overlap.
Net to net There are two possibilities to select the two nets for the net to net measurement method. If you know the names of the two nets, you can choose them in the dropdown in the dialog or you can select them in the visualisation. Either way, you get the shortest distances between the two selected nets on every layer in the list in the dialog while the shortest distance overall is displayed with the additionally activated view settings "draw only selected" and "zoom on selected".
Auto The auto method allows you to specify a maximum distance range as well as from where you want to measure (mouse or object) to which type of elements (lines, pads, surfaces, etc.) you want to measure the distance to. This enables you to easily examine, if the required minimal distances have been met by hovering over the board since the distance will only be displayed, if it falls below the maximum distance you specified.
PCB-Outline The PCB-Outline method examines the shortest distance between a selected object and the next outline while also taking into account from where (object, mouse point, or component) should be measured. A possible use case would be examining, if a component has the necessary distance to the outer edge of the board to be placed properly without problems during production.
to Origin The Origin method checks the shortest distance between a selected object and the middle from the pcb while also taking into account from where (Object Center, mouse point, or component) should be measured.
For all methods a selection history gets added at the bottom of the dialog which allows you to return two every measure you took by simply clicking on it. The visualisation will change and zoom accordingly.