Hello, the tablet computer that can plug in the card must also be able to connect to wifi, and the wifi version of the tablet computer is generally only connected to wifi and can not plug in the card. Which version of the tablet to buy depends on whether you often use the tablet outside where there is no wifi, if so, buy the 3g\/4g version of the tablet that can plug in the card, if not, the wifi version is fine. I personally think that tablet computers do not have much need to buy support 3g\/4g card, after all, card operators charge relatively high fees, and generally use mobile phones instead of holding tablets all the time when going out, but this still varies from person to person. I hope I can help you.