Here document

Output with Expansion

cat << EOF
Text to write goes here
Variables are expanded: $PATH
EOF

Output without Expansion

cat << "EOF"
Text to write goes here
Variables are not expanded: $PATH
EOF

Ignore Tab Indentation

cat <<- EOF
Text to write goes here
    Tabs are ignored, so you can indent the source code without affecting the output.
    If you do want to indent the output, do it with spaces
EOF