The Merge Surfaces command allows users to combine two surfaces into a third one. To do this, navigate to the surfaces tab and select 'merge surfaces'. Assign a name to the new surface, such as 'combined of the FG and survey'. The merge surface is created from both surfaces, with data from surface two replacing data from surface one wherever they coincide. Select the first surface, then the second surface, and optionally set a clipping boundary. Users have options for merging, such as 'replaces existing', 'keep maximum', and 'keep minimum'. After selecting the desired options and clicking 'okay', a new surface is created, representing a combination of the two original surfaces. This new surface is essentially a paste and will not update if changes are made to either of the original surfaces. The process results in a third surface that combines the data from the two initial surfaces, providing a comprehensive view of both. This feature is useful for creating a unified surface from multiple data sets.