RNA editing is a biological process that alters the nucleotide sequence of RNA molecules after they are transcribed from DNA. This modification can change the information carried by the RNA, potentially affecting how proteins are produced. There are different types of RNA editing, including A-to-I editing, where adenosine is converted to inosine, and C-to-U editing, where cytidine is changed to uridine. These changes can influence gene expression and protein function, playing a crucial role in various cellular processes and contributing to the diversity of proteins in organisms.