<style> tag is used to add internal stylesheet in an HTML document.
<style> tag can be added inside <head> or <body> element. But it is recommended to include them inside <head> tag for organizational purpose.
You are free to define multiple <style> elements in a single HTML document. They will be applied in the same order they are included in the document.
<!doctype html>
<html>
<head>
<style>
p {
color: red;
}
</style>
</head>
<body>
<p>This is my paragraph</p>
</body>
</html>