PHP.ini contains the configuration of a server/website. Basically it contains the maximum upload size, maximum post size, register value and others. So it is important for the server and web site. Because all the information is here and your server will follow this information.
Microsoft gives some default and nice sounds inside the windows OS. This sound is different based on OS & task. You will enjoy different sound in XP, Windows 7 & windows 8. But if you want to change the sound then you can easily change it in very easiest way.
If you have more then one gmail account and want to login all of them at once you can add them but you can’t send an email from this address. To do this you need to forward them, and then you can send an email from multiple address but you are logged in one account.
If you have one or more Gmail account and want to sign in all of them at a time, then I want to say: yes you can. And Google give you an option to add and sign in multiple accounts at once. You can sign in all the gmail account which you’ve added with the account which you have logged in.
Facebook allow their user to upload photo, video & share, tag with their friends. However if you want to see your friends photo, video you can see them but Facebook don’t have an option to download this photo, video easily. Same process for any page you have like.