the application they want, on the address of the other computer Server computer 10.0.0.3 25: Mail server 80: Web server 22: SFTP server Client computer Address: 10.0.0.1 Outlook Client computer Address: 10.0.0.2 IE / Firefox Connecting to other programs over a network
Example: most offices ban the ports used for Skype Server computer 10.0.0.3 25: Mail server 80: Web server 22: SFTP server Client computer Address: 10.0.0.1 Outlook Client computer Address: 10.0.0.2 IE / Firefox Firewall Firewalls
✤ Source is available, but author still retains copyright ✤ License may specify that modified copies of the work are kept available ✤ Firefox, Java, Linux, parts of Mac OS ✤ Used when support services are sold (eg, IBM, Red Hat), it helps get products to market faster (Apple), or other reasons.
the time it’s human error ✤ The person making the program ✤ The person using the program ✤ Common problem: certain user inputs aren’t checked by the program.