what does "my.package.dir" mean?

[chiaoyi]

I download a R markdown template. And at the beginning of .rmd file, it has such codes:

# Setup package dir
my.package.dir <- "[dir to package folder]"

# Define directories
my.dir <- "/Users/zhaoyao/Documents/AAE 772/hw3"
hw.dir <- "/Users/zhaoyao/Documents/AAE 772"
# Set directory
setwd(my.dir)

What does this mean? What should I put in brackets? What's the differences among these three dir?

I put my data set in the my.dir. Is this correct?

[andresrcs]

We have no way to know without seen for what is used later in the code, you have to share more information with us.