Simple Random Sampling :-

1) Here selection is done randomly ie. It allows every individual has a chance to be selected in the sample.
2) This method is also called as a lottery method.
3) Here a complete list of individuals within the sampling frame is required.

Convenience Sampling : -

1) Here a selection of individuals is done in groups which are easily accessible.
2) This method is also called as accidental sampling or opportunity sampling.
3) Here no any requirement of list of an individuals.