It can be confusing for some people to know the terms that people are not familiar with. Transgender and transexual may seem the same in the beginning but you have to remember that the term “transgender” refers to someone who changes his/her gender from the one that he/she is assigned to at birth.
When you say “transexual,” this is known to be more specific. The person would like to change to the type of gender that he/she feels will be more appropriate for him/her.
There are some men and women who are transgender who will not become transexuals. Basically, Being transexual is a narrow category that can be placed under being a transgender.