The Merge function is similar to the mosaic tool of ArcMap, where several raster layers and files can be combined to a new raster dataset (see section 6.6.1. for more information).
- Go to Raster.
- Select Miscellaneous.
- Choose Merge.
- Select the input raster images (or even a whole directory).
- Create one single output raster file in a destination folder.
- Enable the lowermost checkbox so that the new raster image will be added directly to the project.