my fellow Americans? My fellow students?

My fellow students, means classmates, or just alumni - the same school, same year, same classroom? specific?

The term "fellow students" generally refers to classmates who are enrolled in the same school at the same time, regardless of whether they were in the same classroom or not. It does not necessarily imply that they were in the same classroom, but rather that they attended the same institution during the same academic year. However, the context in which the term is used can sometimes make it more specific or narrow in scope, depending on the speaker's intent.

Versus: 

my fellow americans?

The term "my fellow Americans" is a more specific and narrow term that refers to individuals who hold American citizenship. It is often used by politicians or public figures to address the American public as a whole, or to create a sense of shared identity or community among the citizens of the United States.

The phrase "my fellow Americans" can also be used in a more personal context, such as in a speech or conversation among friends or acquaintances who are American citizens. In this context, the phrase may be used to emphasize a sense of unity or shared experience among the group.

Overall, the term "my fellow Americans" is a more specific and narrow term than "fellow students," as it refers specifically to individuals who are citizens of the United States.