Sometimes they are made with better fabrics, but if you put on jeans from a department store and than jeans from a designer store, you might not see a difference. Most people just buy name brand to look more expensive.
Brands clothes actually are made better because they have their name/reputation to protect. Higher brands have more money to spend on better quality fabrics.
Name brands are better if you buy them from a department store. It has been know that buying from outlet stores has a cheaper quality of material for the same design. They do not wash well and don't last as long. Pay a little more and you will have a fashion that fits well and looks great.