Brand identity design what is it?
Every brand has it's own identity. Brand identity is what a whole brand is - the brand name, logo, style, visuals, all those pieces adds together and makes a strong message of a brand, which is then brought to people. A brand identity design is a bit different, it's those pieces: logo, style, visuals, those pieces designed with consistency across each other to build the brand message. To succeed, every company needs an effective brand identity design, which would fit the quality of their products, services, style. Companies, which maintains effective consistency across brand elements, win markets, win customers.
People hire graphic designers not for 'fancy' looking graphics, they hire them to make an appropriate designs for their industries, so they can win their target audience, win against their competitors.
A brand is simply a business, company, it can be even a freelancer(like me), that means I'm a brand myself.
Brand identity design is built to build customers trust, loyalty, to make people believe in a brand, to make a brand memorable. And by how people understands the delivered message, how they believe in it, how they see it - it builds a brand image. A brand image is built by people, by customers, not by brand itself, but the better brand identity design, the better brand image accuracy will be.