difference of coding and error detection

I am a newcomer in telecommunications industry,I am very confused between coding of technology systems used in mobile technologies like GSM,CDMA,GPRS and the error correction used in these systems.Does the coding like for example convolutional coding in these systems itself effectively managed the data rates and error corrections by itself?Or is there another techniques like forward error correction used separetly from the convolutional coding techniques to correct the errors?

Please help me as I am very confused.