This is a great article where various experts in the fields of logo design and branding share some design thinking about the differences between graphical logos and logos that incorporate letters and words.
These days, many large brands have complex identity systems that may include both image-only logos and combination logos that include a letter mark or word mark.
Initially, we were thinking of companies like Mastercard, which overhauled its logo (with the help of Pentagram) in 2016. The company name, which once had been so central to the logo, was moved to an auxiliary position, allowing the very recognizable image—two overlapping circles, one red and one yellow—to speak for itself.
This trend—logos that are more graphical—seems to be hastening, in part because our world of small screens requires it.
Kit Hinrichs, principal and creative director of Studio Hinrichs, cautions designers not to be too literal when creating a logo that depicts what a company does …”The best logos are the ones in that allow what the company does to evolve and change—without having to change the logo every five minutes. I think that’s an important thing to keep in mind when doing any kind of branding.”