Widow: A widow is a word or line of text that is forced to go on alone and start its own column or page.
Orphan: An orphan is a single word at the bottom of a paragraph that gets left behind (think Annie pre Daddy-Warbucks).
Why does this matter? An orphaned word at the bottom of a paragraph creates an interruption in the flow that breaks the reader’s focus. This break is caused by the unintended white space that calls more attention than necessary to the single word. Similarly, a widow (line or word of text that jumps to the next page) divides the thought in the sentence.
As graphic designers, we adjust the space between words and/or letters to avoid widows and orphans as the final step in the design process. This is is important no matter if the project is a website design, PowerPoint presentation, report, brochure design, invitation or any other design that includes text.