Any text outside PHP tags is automatically sent to the browser. This is as you would expect. Chapter 18, "Network" deals with the decision to send text via a PHP function. PHP offers three functions that simply send text to the browser: echo, print, and printf.
The echo function sends any number of parameters, separated by commas, to the browser. Each will be converted to a string and printed with no space between them. Unlike most other PHP functions, the echo function does not require parentheses. In fact, echo is more of a statement than a function.
<? echo "First string", 2, 3.4, "last string"; ?>
As text is sent to the browser via functions like ...