What is use of these tags??

<meta http-equiv="X-UA-Compatible" content="IE=7" /> <meta http-equiv="X-UA-Compatible" content="IE=100" /> <!-- IE8 mode --> <meta http-equiv="Cache-Control" content="no-store" /> <meta http-equiv="X-UA-Compatible" content="chrome=1"/> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> What is use of the above tags