I watched the webinar too and he probably said "Substance materials", which is more accurate.
Like 4u2ges explains, the various texture maps (Diffuse, Bump, Metallic, etc.) are based on the settings in the Substance material and are dynamically calculated. Once satisfied you can save resources by "baking" the textures, i.e., make them permanent.
Another way to save resources that was mentioned is sharing the same texture if it is used on multiple surfaces, so that only one copy is needed.