What does Invoke a System Command means in R?

I have following code to execute but I found that system(eval is working behind the scene. I want to know what does it do ? I have found one resource but it does not explain in detail!

cmd.command.line.input <- "C:\Program Files\R\R-3.4.3\bin\R.exe" CMD BATCH C:\Users\myusername\Documents\R\Send_Outlook_Email.R"
system(eval(cmd.command.line.input),intern=F,show.output.on.console = T,invisible=F)

R to execute but could not understand what does system(eval do ?

https://stat.ethz.ch/R-manual/R-devel/library/base/html/system.html