00 is not a telephone country code, nor is it part of a country code. Telephone country codes never begin with zero. Many countries use 00 as an international access prefix (although many countries use various other prefixes) before dialing a country code. For example, to call Fiji (country code +679) from countries that use 00 as the international access prefix, you would dial 00 679.
Also, mobile numbers use the same telephone country codes as landlines, with the exception of special global service codes like +870 or +881 for satellite phones.
(The plus sign means "insert your international access prefix here." From a GSM mobile phone, you can enter the number in full international format, starting with the plus sign. The most common prefix is 00, but North America (USA, Canada, etc.) uses 011, and many other countries use different prefixes.)
'00' is not part of the country code, it is a commonly used international access prefix. Country code +41 is Switzerland, and +41 79 is a mobile.
'00' isn't part of the country code, it is a commonly used international access prefix. Country code +49 is Germany, and +49 15 is the beginning of a mobile number.
'00' is not part of the country code, it is a commonly used international access prefix. Country code +256 is Uganda, and +256 78 is a mobile.
'00' isn't part of the country code, it is a commonly used international access prefix. Country code +886 is Taiwan(Republic of China), and +886 9 is a mobile number.
'00' isn't part of the country code, it is a commonly used international access prefix. Country code +233 is Ghana, and +233 24 is an MTN mobile.
'00' is not part of the country code, it is a commonly used international access prefix. Country code +90 is Turkey, and +90 542 is a Vodafone mobile.
'00' is not part of the country code, it is a commonly used international access prefix. Country code +972 is Israel, and +972 54 is an Orange mobile.
'00' is not part of the country code, it is a commonly used international access prefix. Country code +91 is India, and +91 9819 is a mobile in the Mumbai area. The primary carrier for a +91 9819 number is Vodafone, but due to number portability, the number may now be on a different mobile provider's network.
'00' is not part of the country code, it is a commonly used international access prefix. Country code +221 is Senegal, and +221 76 is a Sentel Tigo mobile.
00 is a commonly used international access prefix, not part of the country code+670 is the country code for Timor-Leste (East Timor)33 is the beginning of a landline number in Dili
00 is a commonly used international access prefix, not part of the country code. Country code 33 is France. A number beginning with +33 977 is a non-geographic number (neither a regular landline nor a mobile phone).
Country code +7 is Russia and Kazakhstan; a number beginning +7 9 is probably a mobile in Russia.