Surfaces for your projects
Textures help to create surfaces with a realistic „coat“. They bring a piece of the real world into digital image editing which is often way too „clean“. You can include structured areas and convert them with different shapes. In this way you can create high-quality compositions.
In general, I would recommend to get approval from the designer when using his or her textures especially when you want to use the results of your work commercially. So you can be sure to avoid unpleasant surprises. And the designer will be delighted to know how his or her textures are used (even if the general approval is already posted online).