In Apps Script, String objects are used to represent a sequence of characters. String objects in Apps Script are similar to strings in other programming languages and can be manipulated using various methods provided by the String class. Some of the commonly used methods include substr, indexOf, slice, and replace. String objects are used extensively in data manipulation, text processing, and form validation in Apps Script. In addition, the ability to concatenate, trim, and convert case makes it easy to format and normalize strings for various purposes. Overall, String objects are a powerful tool in Apps Script for working with text data.