Postfix operators ([], ., ->, ++, --) have the highest precedence in C, followed by unary and then binary operators.

The 'volatile' keyword tells the compiler not to optimize accesses to a variable, as its value can change from external sources (hardware, signals, etc.).

Strings in C are represented using double quotes and stored in character arrays. Single quotes are for single characters.

In C, when both operands are integers, division performs integer division, discarding the fractional part. 5/2 = 2.

A signed char is 1 byte (8 bits) and can represent values from -128 to 127 using two's complement representation.

The escape sequence \n represents a newline character that moves the cursor to the next line.

The main() function implicitly returns int type, which indicates the program's exit status (0 for success, non-zero for failure).

Variable names in C must start with a letter or underscore, followed by alphanumeric characters or underscores. '_variable123' is valid, while '2variable' starts with digit, 'var-iable' has hyphen, and 'var iable' has space.

The sizeof operator returns the size in bytes of a data type or the allocated memory for a variable.

The stdio.h (Standard Input Output) header file contains declarations for printf() and scanf() functions.