# 2.8 Summary

In this chapter, we mainly introduced the 25 Go keywords. Let's review what they are and what they do.
```Go
	break    default      func    interface    select
	case     defer        go      map          struct
	chan     else         goto    package      switch
	const    fallthrough  if      range        type
	continue for          import  return       var
```	
- `var` and `const` are used to define variables and constants.
- `package` and `import` are for package use.
- `func` is used to define functions and methods.
- `return` is used to return values in functions or methods.
- `defer` is used to define defer functions.
- `go` is used to start a new goroutine.
- `select` is used to switch over multiple channels for communication.
- `interface` is used to define interfaces.
- `struct` is used to define special customized types.
- `break`, `case`, `continue`, `for`, `fallthrough`, `else`, `if`, `switch`, `goto` and `default` were introduced in section 2.3.
- `chan` is the type of channel for communication among goroutines.
- `type` is used to define customized types.
- `map` is used to define map which is similar to hash tables in other languages.
- `range` is used for reading data from `slice`, `map` and `channel`.

If you understand how to use these 25 keywords, you've learned a lot of Go already.

## Links

- [Directory](preface.md)
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