Title Case versus Capitalize Each Word
Capitalize Each Word does exactly what it says: the first letter of every word becomes uppercase. Title Case follows the style used by most English headline guides, capitalizing major words while keeping short articles, conjunctions and prepositions such as a, an, the, and, but, or, of, in, on, at, to and for in lowercase, unless they are the first or last word. For example, the lord of the rings becomes The Lord of the Rings.
Sentence case lowercases everything and then capitalizes the first letter of each sentence. It cannot know which words are proper nouns, so names like Paris or NASA will need a quick manual fix afterwards.
Alternating case and accessibility
Alternating case flips between lower and upper letters and is popular for playful posts. Be aware that screen readers may read it awkwardly and it is harder for people with dyslexia to read, so avoid it for important information.