What are dual Sim cards?

What is the reason for having a cellphone with dual SIM cards and who makes phones that contain dual SIM cards?

• Answer:

  Dual Sim can allow the user to cut down on devices. Some examples: A dual sim phone can accept two services and numbers in one phone. For those who have a work line this allows the person to carry only one phone for both personal and professional purposes. In some cases this is better than having two phones or one phone used for both. You have separate numbers and separate contact lists. For people who travel between countries this feature allows them to have sims for both places in one phone making it less likely a sim will get lost or forgotten. Indeed some people use this within one country when they travel to areas where their home carrier is not as useful. Most major manufacturers make dual sim versions of common phones you see every day. The technology is more popular in some areas than others. For example its unlikely you will find one in the USA without some serious digging and likely buying it via another country; but in places like Europe or the Middle East they are very common. Motorola, Nokia, Lenovo, and Xiaomi all have pretty large selections of both feature phones and smartphones that have this option.