And they have a good relationship with Turkey- and for now the Peshmerga do not get along to well with the PKK.
Here's A Map Of The Kurdish Nation - Business Insider
The Kurds in Iraq have actually expanded the total territory they control by 40% since ISIS took over Mosul. This has fueled fears in Iraq that Iraqi Kurdistan may declare itself a fully independent state.
Iraqi Kurdistan already runs itself in much the same way an independent nation would. It has its own armed forces, and it has been selling its own oil for half the price of what the rest of Iraq charges through a pipeline to the Turkish port of Ceyhan. It is estimated that the Kurdish region contains a quarter of all of Iraq's oil. That figure is likely an understatement now that the Kurds control Kirkuk — a key oil hub.
KRG, PKK make unlikely allies as they battle IS together - Al-Monitor: the Pulse of the Middle East
In the past three years, there have been political conflicts between the two biggest Kurdish political parties, the Kurdistan Workers Party (PKK), led by Abdulla Ocalan, and the Kurdistan Democratic Party (KDP), led by Masoud Barzani, over ruling Rojava and sharing power between their two affiliated parties; the pro-PKK Democratic Union Party (PYD) and the pro-KDP Kurdistan Democratic Party-Syria (KDP-S).