Service providers provide numbers on the basis of the services customers avail. The various kinds of numbers available are landline numbers, cell phone numbers, unlisted numbers, and unpublished numbers.
Landline numbers : These are permanent numbers and are transmitted through cables rather than airwaves. The numbers usually contain the area code and exchange code. They are fixed according to a particular location and cannot be used for other locations. A third party cannot intercept this line unless there is physical access. Landlines provide clear and secure connectivity. The numbers are available for public viewing in directories and other services.
Cell phone numbers : Service providers provide these numbers to cell phone users. The service providers also have fixed numbers, which are denoted by the first 2 or 3 digits. The cell phone number always starts with this number. These numbers generally do not appear in directories to maintain the privacy of the user.
Unlisted numbers: Numbers, which do not appear in directories or are not listed anywhere, are known as unlisted numbers. Users request their providers to withdraw their numbers from public view. They do this to maintain their privacy and for security reasons. This also helps them to avoid sales calls and other unwanted calls. This facility is provided at a cost as per the provider.
Unpublished numbers: The numbers that haven't been published in directories are known as unpublished numbers. These numbers may have been formed at a later date than the date of the telephone directory being published. They are not withheld for any specific reason, and will be published in the next issue or at a later date.
