From the Overview: "The Islamic Republic of Pakistan is a parliamentary democracy in which the prime minister is head of government and the president is head of state. A bicameral parliament is comprised of a 342-seat National Assembly (NA) and a 104-seat Senate, both with directly elected representatives from each of the country's four provinces (Balochistan, Khyber Pakhtunkhwa or KPk, Punjab, and Sindh), as well as from the Federally Administered Tribal Areas and the Islamabad Capital Territory (the quasi-independent regions of Azad Kashmir and Gilgit-Baltistan have no representation). [...] Senate powers are limited, and only the NA can approve budget and finance bills. Historically, constitutionalism and parliamentary democracy have fared poorly in Pakistan, marked by tripartite power struggles among presidents, prime ministers, and army chiefs."
CRS In Focus, IF10359
Congressional Research Service: https://crsreports.congress.gov/