1. Discuss why it is so important for all application builders to always check data received from unknown sources, such as Web applications, before using that data. 2. Why should Web site operators that allow users to add content, for example forums or blogs, carefully and consistently patch and configure their systems

1. It is so important for all application builders to always check data received from unknown sources before using that data. This is because of the Security related reasons and vulnerabilities .For example the data received might contain harmful hidden viruses.  Web applications are accessed by internet and these are the most vulnerable to attacks by hacker or intruders using harmful data containing malware. This can cause security breaches due to the security flaws or bugs in Web applications. So to overcome such security risks which can cause damage in the Web applications, data from unknown sources should be checked.

Explanation:

2. When the Website is being used and running, there is a room for possible glitches or other bugs and issues. To understand, handle and address  issues successfully, the website operators carefully and consistently patch and configure their systems. The administrators collect the user data which enables them to have enough data in order to make the requisite alterations or improvements in the website. This also helps to improve the website performance. The patching and configuring of systems fix problems in the website which reduces the risk of website damage and the website works smoothly this way. Moreover it identifies vulnerabilities, solve configuration issues and upgrades in website features provide additional capabilities to the website.