Whats the use of permissions ?

[chetan dhumane]

Whats the practical use of <uses-permission> tag , how it helps to provide security ?
Anyone can embed this tag in his/her application and can use it .

Thanks in advance .

[Lester Burnham]

Anyone who wants to download an application from the Android Market will be warned about which permissions the application uses. So the user can make an informed decisions about whether or not he wants to use it. I have rejected several applications that looked interesting, but that needed (for some unexplained reason) more permissions that I thought were necessary. Access to contacts and calendar, especially when combined with internet access, is especially suspicious.