What is a material.cs file? Any idea what materials and textures are?

I'm trying to create my first mod for BeamNG. I have an awesome mesh, but the textures are pretty dull. Due to my lack of experience with Blender, I don't know how to work with or change materials and textures. I don't exactly understand what they are either. Is a material something you can export through Blender? Can you create them in Photoshop? Is it something you create through coding? I have absolutely no idea what they are. The only thing I've established is that materials and textures change the visual appearance of the mesh. From what I've seen, I'd guess that the texture is the picture/color element, and the material is the code element. I'd really like some help with creating a custom texture and material. If anyone knows of any useful tutorials/resources, or has some insight to share, please let me know. I'm not begging for someone to do the work for me. Thanks in advance!