what do the digits in a phone number mean
Telephone number The number contains the information necessary to identify uniquely the intended endpoint for the telephone call. Each such endpoint must have a unique number within the public switched telephone network. Most countries use fixed length numbers (for normal lines at least) and therefore the number of endpoints determines the necessary length of the telephone number. It is also possible for each subscriber to have a set of shorter numbers for the endpoints most often used. These "shorthand" or "speed calling" numbers are automatically translated to unique telephone numbers before the call can be connected. Some special services have their own short numbers (e.g., 1-1-9, 9-1-1,1-0-0, 1-0-1, 1-0-2, 0-0-0, 9-9-9, 1-1-1, and 1-1-2 being the Emergency Services numbers for China, Japan, India, South Korea, Taiwan and Sri Lanka; Canada and the United States; Israel (Police); Israel (Paramedic); Israel (Fire); Australia; the United Kingdom, Ireland, South Africa, Poland, Saudi Arabia, the United Arab Emirates, Morocco, Macao, Bahrain, Qatar, Bangladesh, Botswana, Ghana, Kenya, Hong Kong, Malaysia, Mauritius, Singapore, Zimbabwe, Trinidad, Tobago, New Zealand, Kuwait, the European Union and the Philippines respectively.)
Telephone numbers in the Republic of Ireland Irish area codes vary in length, between one and three digits (excluding the leading 0), and subscribers' numbers are between five and seven digits. A migration to a standard format, (0xx) xxx xxxx, is in progress; however, to avoid disruption, this process is only being carried out as needed where existing area codes and local numbering systems have reached full capacity. There is currently no plan to move to a closed numbering system.