The writings of Marcus Aurelius, commonly called the Meditations, didn't actually have a title given by the author himself because it was never intended to be published or even read by other people. It is also the only work by him, so if he is the author then they should all just be different translations of the same text.
The earliest copy we have is itself a Greek translation of the original Latin writing so there is no definitive version, and some prefer to translate as literally as possible while others take liberties with the language in order to try and convey the original meaning a little better. Some copies include extra notes by the author and other materials which may also be of use. Which of these features are desirable depends on the reader's preferences and why they are reading the book
On a personal note, for a translation that is slightly in the latter liberal-translation category (so not ideal for academic study of what Aurelius said down to the exact word) but great for someone who wants to still read his thoughts, I very much recommend the version titled The Emperor's Handbook by Hicks and Hicks - that is my go-to recommendation for introducing any 'normal' person to stoicism.