In some situations we need the internal name of a field instead of its display name. For most customizations it is even better to use the internal name, because the internal name will not change, but the display name could be changed by any user with the proper permissions.
Getting the internal name is not that difficult. For the list or library open the settings page and in the settings page click the column, for which the internal name is needed. This will open the settings page for the column. In the address bar of the browser click into the address an scroll to the end of the value in the address bar.
Here we have the parameter “Field=internalname” (in the image above it is “Field=Status”). That means in the example in the image, the internal name for the field with the display name “Issue Status” is “Status”.