Country calling codes are numerical prefixes used to dial telephone numbers internationally. Each country is assigned a unique code, which typically starts with a "+" sign followed by one to three digits. For example, the code for the United States is +1, while India has the code +91. These codes help direct calls to the correct country when dialing from abroad. When making an international call, you must first dial the international access code, followed by the country calling code, and then the local number. This system ensures that phone networks can route calls accurately across different countries, facilitating global communication.