Or Fire Blast but not Flamethrower? Blizzard but not Ice Beam? Hydro Pump but not Surf? How about vice versa? Can any Pokemon learn Thunderbolt but not Thunder? Flamethrower but not Fire Blast? etc.
If a name is repeated, it means that that Pokemon can learn their move through more than one method, yet cannot learn the other move at all.
The formatting of this answer took more time than the actual collection of data. Thus, if you want to thank me for something, thank me for making this answer look presentable!
Hope I helped. :)
Source: The moves' respective Serebii pages.