1 and nodejs mainly run on the server side, and the most common one is to be an HTTP server. Of course, you can also do other things.
2.nw.js, formerly known as node-webkit, is a project integrating nodejs and webkit browsers. It is mainly to write cross-platform client applications, write programs with HTML+CSS+JS, and then package them to run on NW.js The programs can use local resources and network resources, which is very convenient for cross-platform. It can use technologies that can be used in Web applications, but it can't, such as reading and writing local files, using serial ports and so on. As long as your code is not tied to the operating system, it is very convenient to get the programs used under Windows to Linux-many times it is just a package.
3. To talk about the shortcomings of nw.js, first of all, it should be that this thing is too big, the main program is 5,60m, and some are mixed together, about 80M. If you write a small program, it is really bloated; The second is the running speed, which is similar to other Web applications. It's really bad when you want speed.