master, colored green, and this branch makes up the starting point or "trunk" of the tree. When Hello.txt was created, "Hello" was written to the file and it was saved, or commited, making it the first commit on this file's tree (a sideways tree that grows from left to right, over time).
master, meaning each user now has a copy of Hello.txt as it existed at the second commit.
masterbranch. This means that the
masterbranch everyone uses will now have Kayla's changes to the file. The merge is represented by the dotted-line arrows stemming from both Kayla's version and from the
masterversion of the file. This merging combines the two versions of Hello.txt (for our purposes magically) to make a new version of the file that reads "Hello World It's Kayla!".