these are the type of frames.
but it comes in different category.
means there are two frames which is
based on identifier field are standerd and extended frame.
based on type of data that is DATA FRAME and RTR that is Remote Transmission Request which is request for data.
if we want to send remote frame then we have to select the identifier field that is 11-bit (STANDERD) or 29-bit (EXTENDED) FRAME and then followed by next frame structure.