Dictionaries list "completion" as a definition for both of these words. I'm trying to figure out the difference between them.
Some online sources say 完成 is used when you finish making something and 完了 is used when you are finished doing something, but I'm kind of skeptical about this because I've seen sentences with 完成 used with 仕事, such as this one:
その仕事{しごと}は大部分{だいぶぶん}完成{かんせい}した。
The work has been almost completed.
What's the difference between them?