The Legislature
Parliament as we usually refer to it is responsible for making and changing laws. The head is the speaker of parliament.
Duties
The First function of parliament is to make laws.
Deliberations, debates of opinions to arrive at a great educative value and value for money of the projects for the people
They serve as custodians of national finances. They approve finances before the executive can make use of them.
They have oversight roles of supervising the executive
The legislature has some power of the judiciary which can impeach a president