I think one of the difference is that by using SVM you can reach higher ratio in comparison with normal PWM.

SVM is machine learning and PWM is digital communication.

1) pwm- pulse width modulation technique

Old technique. It only offers the ckt turned off and turned on for certain time period. It uses to generate the pulses for conventional voltage source inverter.

2) space vector modulation technique- these techniques are the novel approaches. Recently multi level inverters are gaining its interest.To operate these inverters more switching sequences are required. Svm offersmore switching sequences as cpmpare to pwm techniques and the regulation is also more easier