so basically I will be talking about how does sim card work, how sim card works, what does a sim card do in a smartphone, what does a sim card hold, Sim Card Information and many more things are going to clear today I swear. What Is SIM Card? While eating something (something means Mom’s delicious food or chicken republics food ) we always see how its look and then we start eating. The reason behind saying it is before going on how does sim card work first we need to understand what is sim card? So, SIM card’s full name is Subscriber Identity Module and it uses to talk to our loved one. How Does Sim Card Work? Now after seeing food I mean after knowing what is sim card let’s know How Sim card works. See its full form, it’s saying Subscriber (you) Identity (your phone) module that means your sim card knows what type of phones you are using. So, when you make a call this happens : When you dial any 11 digit number and press call button. Your phone sends your sim card id number with an authentication key (something like a password) that is in your sim card to the operator like Airtel, 9mobile, Glo, Mtn Now after receiving your sim card id number and your authentication key, it generates a random number (assume 12345) and uses authentication key to generate a response number (assume 88888) at the same time. After that the random number generated by your operator (12345) sent back to your phone, now after receiving that random number, your authentication key will generate a response number (88888). If both random number match, your provider will recognize that it’s you and after that, it connects to whom you want to call. If your number doesn’t match you can talk that’s why sometimes your call doesn’t connect and it keep sounds like beep beep beep. Few Known Sim Card Information (Sim Card Facts) Let’s know something more about your sim card. It can store up to 600 contacts in it. First sim cards used to come in standard/mini size, then it starts coming in Microform and now we all are using in nano form. You might have remembered first sim card used to come in 64k variant and after that, it is coming in the 128k variant. You can say it brain of your smartphone. It is made of plastics. What Does A Sim Card Do In A Smartphone? It connects you to the whole world. What Does A Sim Card Hold As I said above it can save your contacts up to 250 but what is the need for it. We all now store all our contacts on Google cloud thanks to android. Does A sim Card Hold Pictures Of course not. It’s is of 128KB only. (Want to kill this little thing). What is 64K, 128K Written on Sim Card Means? That’s mean our sim card is getting smarter day by day. In the 128k variant, you can take backup your contacts, store more messages and phonebook numbers as compared to the previous variant. @rayne words: So guys, I successfully made a post on “How Does Sim Card Work? Love The Most Ignored Thing , how does sim card work, how sim card works, what does a sim card do in a smartphone, what does a sim card hold, Sim Card Information”. I have first searched on the web about it and finally, the result in front of yours. I don’t think you will face any problem regarding this post while understanding or implementing BUT if you are facing any problem regarding this post just feel free to comment on the comment box . I’ll be back to you as soon as possible with working and satisfying answer. ALWAYS REMEMBER WE ARE FRIENDS.