How many wives did the Messenger of Allah, peace and blessings be upon him, have? And was Maria al-Qibtiyya one of them? And what is the meaning of "Imaa' (slave-women)"?

The discrepancy in the number of the Prophet's wives (peace be upon him) is due to Rayhanah bint Zayd al-Nadariyyah. Those who considered her a wife counted twelve, while those who did not, but rather a slave-girl who was taken as a concubine by right of ownership, counted eleven. As for the saying of fourteen, its reason is the disagreement regarding counting those with whom he contracted marriage but did not consummate it. Mariyah al-Qibtiyyah was a slave-girl taken as a concubine by right of ownership and not a wife. A slave-girl is a female owned. This is a minor disagreement that does not entail any legal ruling.