What is the function of the paint format button in spreadsheet applications?

The paint format button in spreadsheet applications serves the important function of copying the formatting from one cell and applying it to another cell. This functionality is essential for maintaining consistency in the presentation of data, allowing users to quickly replicate styles such as font size, color, borders, and number formatting without manually adjusting each property. The ability to easily copy formatting saves time and effort, especially when working with larger datasets where uniformity enhances readability and professionalism.

The other options do not align with the specific function of the paint format button. Changing the overall theme of the spreadsheet relates to broader aesthetic changes, while erasing cell contents involves deleting data rather than copying formatting. Sorting data is a process used to organize information numerically or alphabetically, which is unrelated to the formatting capabilities provided by the paint format button.