{{}}disappear，What is the meaning of\{{}}

[lemoncool]

After setting the template, the variables in {{}}disappear after vue init ****/** my-project， Looking at the source code, I see that"\"has been added before {{}}, such as <h1>\{{msg}} </h1>, so I would like to ask, What is the meaning of "\"，and should"\" be added before{{}} all variables?