To understand and learn the C programming language you have to first understand the basic building blocks of C language which includes Tokens, Semicolons, Comments, White spaces etc.

>> Tokens: In C programming language 6 types of tokens are available that are

1). Keyword
2). Identifier
3). Constant
4). String
5). Operator
6). Special Symbols

>> Semicolons are used for the termination of the Statement

>> Comments are added in C language in between these symbols /* */

>> White Spaces are ignored by C compiler.

For Further reading check: http://gatecrack.org/basic-building-blocks-in-c-programming-language

Thanks

In data structure tree traversal techniques are of three types

1). Inorder Traversal
2). Preorder Traversal
3). Postorder Traversal

In Inorder Traversal left subtree is traversed first in inorder fashion, then root node and at last right sub tree is processed
In Preorder traversal root node is traversed first then left sub tree in inorder fashion and at last right sub tree in inorder fashion
In Post order traversal root is traversed at last first left subtree is traversed, then right subtree and at last root is traversed

Ref: http://gatecrack.org/tree-traversal-techniques-in-data-structure-with-example/