Set theory all granites are igneous rocks, but not all igneous rocks are granite.
Igneous rocks are rocks that are formed by fire and heat. Molten crust material is melted to form igneous rocks.
Granite is the most common form of igneous rocks on the continental plates. Granite is reworked crust that is formed as crust is meted and reworked.
Basalt is the most common form of igneous rocks on the ocean plates. Basalt comes directly from the mantle. It is darker and more dense than Granite.
Other types of igneous rocks exists besides the two main forms granite and basalt, such as obsidian
Granite is a form of an igneous rock but it is not only form of igneous rocks.