The original Samsung Galaxy logo was introduced along with the Samsung Galaxy (GT-I7500) phone on 27 April 2009.
The "Samsung" text is modified.
Samsung Galaxy introduced a new logo in 2015. The "Samsung" text was replaced with the Samsung logo, and "Galaxy" got a new font (the custom-designed Samsung Sharp Sans) with only the first letter capitalized. This logo came with the Samsung Galaxy S6 and Galaxy S6 edge. It was first used in the Samsung Galaxy Unpacked 2015 event, followed by Samsung Galaxy models from 2015 to 2018.
After the launch of the Galaxy Note9, a revised version of the Samsung Galaxy wordmark was revealed, with the "Galaxy" text having the same size as the Samsung logo.