I can't speak to 'most image editing programs' but I can tell you that Photoshop allows one to both 'resize' and 'resample' an image.
From this web site:
http://www.designer-info.com/
Came the following:
'At first sight resizing an image either up or down hardly seems to be an issue. In any photo editor you’ll find an Image Size command that lets you change an image’s dimensions. As we saw last month, however, changing an image’s physical dimensions doesn’t necessarily change its pixel dimensions. If the number of pixels remains identical all that is changed is the internal resolution parameter which sets the default size for printing.'
'Rather than Resizing what we need is to explicitly change the number of pixels in the image, a process called Resampling, or Downsampling in this case as we are reducing size. To do this in Photoshop, you need to select the Resample Image option at the bottom of the Image Size dialog which then lets you change the Width and Height settings to the exact number of pixels required (this can also be set as a percentage of the current dimensions). When you click OK, after some processing, the new smaller version of the image will appear.'