Please explain in depth about this simple paging diagram

Main Memory Secondary Memory Operating System rocess P FO F1 F2 F3 F4 Process P-Page 4 First 100 bytes Second 100 bytes Third 100 bytes Fourth 100 bytes Fifth 100 bytes Sixth 100 bytes Seventh 100 bytes Eight 100 bytes Page 0 Page 1 Page 2 Page 3 Page 4 Page 5 Page 6 Page 7 Process P- Page 0 Process P Page 2 Process P- Page 1 Process P Page 7 FS Process P Page N and so on... Pages for other processes Page N Pages for other processes Pages for other processes FN