To restrict access to users for certain resources of an application, a process of identifying users becomes a necessity. Authentication enables to restrict a user to access resources by certain ways. It could be a combination of a username and password, a digital certificate, a smart card or a fingerprint reader. The validity of information provided by user helps identify user, so that user is provided access to requested resources. The process of successful identification of user implies that user is authenticated.

After identification of user is over, next step is to determine whether authenticated user has access to resources. The process of determining access to resources for a particular user is known as Authorization. In Windows based systems, resources have an Access Control List, which provides a list of users who have access to that resource. The list also specifies kind of access such as read, write, modify, and delete resource, for each user. For example, if a user requests an ASP page, operating system checks whether user has Read access to page and if user has read permission, then operating system allows IIS to fetch page. The IIS has authorization settings which enable IIS to control access of resources by users. File Access Control Lists are set for a given file or directory using Security tab in Explorer property page.

To access online version of above article, go to http://www.dotnet-guide.com/accesscontrol.html

If you want to purchase a camera phone, consider what quality of photos you need to take. Most camera phones have less than a one megapixel resolution, which produces low-quality images. If you need to take clear photos, look into a camera phone with 3 or more megapixels.

Voice Dialing and Bluetooth are becoming standard in many phones to make it easier and safer for people to use their phones while driving. Voice Dialing allows you to speak a person’s name into your phone, which will automatically find person in your address book and dial number for you. Bluetooth lets you connect a headset to your phone without wires. Some luxury cars are beginning to offer Bluetooth connectivity so that you can take calls in your car through built-in speaker system.

Some newer cell phones are being designed with an emphasis on entertainment. They can be used to play music MP3 files, stored video and even movies, and video games. In general, newer phones are all getting smarter and more specialized.

After you’re done choosing features that you want, don’t neglect practical aspects. Look at how often you will need to change battery, whether screen and keypad are too big and too small. Also, caveat emptor: most cellular providers lock you into a one or two year contract when you purchase a phone from them. If you cancel your service, they will charge you an early termination fee.