A:AnswerIt is smaller and lighter than the T4i, but the T4i has an articulating screen which would be extremely handy in many circumstances - especially shooting video.
A:AnswerNo, this product does not have Wi-Fi. This product works with Secure Digital Extended Capacity (SDXC), Secure Digital, Secure Digital High Capacity (SDHC) cards.
A:AnswerConnectivity simply means that you can connect it to a computer via a cable. Yes, you will need to purchase an SD card to store pics on. It has no on-board memory of it's own but this is typical of most all digital cameras.