You can think of strings as arrays of characters. Strings are commonly used in PHP for storing words and sentences. Strings are also used in PHP for data exchange. That is, strings are used to pass data from one page to another page. Strings in PHP can be found in almost all programs, as most of the tasks are done with the help of strings. Strings are very easy to work with and are easy to use in PHP. The syntax is to enclose the string in double quotation marks. You can also use single quotation marks, but this is not recommended, as there might be instances when using single quotation marks might cause problems in the script.