What is the meaning of the verse, "Whatever a verse We abrogate or cause to be forgotten..." (2:106), and has the last verse of Surat Al-Kafirun been abrogated, and what is the reality of abrogation (nasikh and mansukh)?

Allah Almighty says: "Whatever verse We abrogate or cause to be forgotten, We bring forth [one] better than it or similar to it." "We abrogate" means We bring it to an end. "Or cause it to be forgotten" (with a dammah on the 'nun' and a kasrah on the 'seen') means We leave it and do not replace it, and (with a fat-hah on the 'nun' and 'seen') means We delay it. "We bring forth [one] better than it or similar to it" means We bring what is more beneficial to people or similar to it. As for the last verse of Surah (definition) Al-Kafirun, "To you be your religion, and to me be my religion," it has been said that it was abrogated.