On the concept of relativistic mass

Within the past fifteen years the use of the term relativistic mass has been declining. The term 'proper mass' - simply referred to as 'mass' and labeled 'm' - has now largely replaced 'relativistic mass.' This decline in usage appears to be due to arguments presented in several journal articles, as well as to standard practices in the field of particle physics. This debate consists of arguments as to how the term 'mass' should be defined to maximize logic as well as less confusing. My purpose in this article is to clarify the arguments of the debate and to bring a unifying perspective to the subject. In doing so I will explore the importance of point particles vs. extended objects/ open vs. closed systems. Although I argue for the usage of relativistic mass I do 'not' argue that proper mass is not an important tool in relativistic dynamics.