In a short and accurate answer, there is no significant difference between the TF card and Micro SD card. Its just name difference according to introducing time and companies.
SanDisk has developed a volatile memory device by the name of TransFlash in the past year 2004. Further, they are known as TF Cards. So, no need to ask what is TF card, it’s just average memory storage which we use in mobile phones and camera or GPS devices.