The Brotherhood of Nod follows three Ideologies, of which a commander can utilize two in combat. The three Ideologies are Technology, Industry and Propaganda.
The Brotherhood has access to some of the most advanced technology on the planet. When they first fought GDI in the late 90s, they were already using laser weaponry and stealth devices to turn their tanks and troops invisible. Ever since then, the Brotherhood has been upgrading their technology, making sure that they are always one step ahead of their opponents. Accessing this ideology will upgrade your units with new weapons.
In order to be able to produce weapons and equipment, the Brotherhood has a very large industry base, exceeding the capabilities of some Blue Zones. It was the industry of the Brotherhood that allowed them to mine Tiberium before anyone else could and allowed them to become a superpower. It was also what allowed them to build tanks and vehicles at a fast rate so they could enforce their rule. Accessing this ideology will improve your economy, along with giving some of your vehicles new abilities and replacing some with more powerful variants.
The Brotherhood has always relied on propaganda to increase their ranks. Images of soldiers in black armor, with red visors and pictures of Kane inspire people to join them, to become something they could only dream of. Propaganda has always been a defining feature of Nod, with promises of the next evolution of mankind and access to technology far beyond what the GDI dogs could ever develop, it easily allows people who live in Yellow Zones to join their side. Accessing this ideology will decrease the cost of your infantry by 50%, along with boosting their capabilities.