This is the 14472nd most frequent Korean word.
문자메시지는
"Text message"
Here, '문자메시지는' is used to introduce the topic of text messages and describe their function or usage.
문자메시지는 수단으로 사용됩니다.
Text messages are used as a method.
In this sentence, '문자메시지는' highlights text messages as the subject being described concerning communication convenience.
문자메시지는 친구와의 소통에 편리합니다.
Text messages are convenient for communicating with friends.
The term '문자메시지는' here serves to denote text messaging as an element of focus in the subject matter regarding social platforms.