What does the UPPER function do in Excel?

The UPPER function in Excel is designed to convert all letters in a given text string to uppercase. This function is particularly useful for ensuring consistency in text formatting, especially when you want to standardize entries that may be mixed case or when preparing data for aesthetic purposes in reports or presentations. For example, if you have a cell containing the text "hello world," using the UPPER function on that cell would result in "HELLO WORLD."

This feature can aid in tasks such as preparing data for database entries, ensuring all names or items are displayed uniformly in a particular format, or when comparing text strings where case differences could lead to mismatches. Understanding the UPPER function is key to manipulating text data effectively in Excel.