What is the meaning of widows and orphans in academic and professional writing?

In academic and professional writing, widows and orphans refer to Words or lines of text that are left alone at the beginning or end of a paragraph or page. Widows are lines of text that appear at the top of a page with the rest of the paragraph on the next page, while orphans are lines that appear alone at the bottom of a page. It is considered good practice to avoid widows and orphans for better readability and aesthetics in writing.