is the topic equivalent to sources of shariah?

N how is shura different from legislation? in Pakistan constitution legislation is translated to shura.

I think the 2 topics are one and the same. But yes, you definitely need to differentiate between the primary sources - Quran o Hadith - and secondary sources - Ijtihad, Ijma and Qiyas etc. The primary sources constitute the core Shariah. The secondary sources, are not 'the word of God' per se, and do not carry the same importance. Nevertheless, to discard them altogether is to actually decline to abide by Allaah's commandments.

Shura is different from legislation in that for Shura you didn't have elected representatives. The persons consulted used to be chosen based on the insight of a pious man - either the Prophet himself SallAllahu alaihi va alihi vasallam or the Khulafa e Rashidun. Next, they were qualified in religious as well as worldly ways. Moreover, there top priorities for 'legislating' were Allaah's pleasure, not popularity or re-election or self-serving. To add to it, the final authority lay with the Caliph... you can keep adding more on the same lines if you will...

Best!