I want to understand the bit masking and shifting process in embedded c. Therefore, can anyone explain me the working of below commands in detail?

I am working on ADS1299 and Atmel. Therefore, I am interfasing ADS1299 with Atmel SAM4E. For that I want to be very good at Bit Masking and shifting. Therefore, can anyone help me with understanding those concept by explaining the below lines?? 1. #define SINE_CONTREG_BASE (0x1 << 13) 2. #define SINE_PHASEREG_BASE (0x3 << 14) 3. #define IOPORT_MODE_MUX_MASK (0x7 << 0) /*!< MUX bits mask / 4. #define IOPORT_MODE_MUX_D ( 3 << 0) /!< MUX function D */ 5. PORTB |= (1 << PB2); 6. PORTB &= ~(1 << PB2);