Why does avast! separate the local real protection into different type of real protection like P2P shield, IM shield and file shield? Is there any special function about this ? I recommend avast! to others, they asked me that it seems file shield also scan local softwares reading and writing, so is P2P shield and file shield necessary as well?
some people also think that web shield is unnecessary as well, because file shield could scan local cache of browser.
I don’t know how to explain these question, it is plausible right, but I don’t think these models which were designed by avast! group are needless.
The different shields (P2P, IM, eMail and Web, etc.) are specifically designed to monitor that type of traffic/protocol, e.g. they use a specific protocols and ports to communicate P2P, IM, eMail and Web, etc. all use different protocols to communicate, the avast shields are designed to monitor that specific traffic protocol.
The file system shield is watching for files being created, modified or run on your system, the other shields are generally trying to prevent the malware getting on to your system in the first place.
The web shield is possibly the most effective shield since the greatest majority of malware comes from the internet. Whilst browsing, if you happen across a hacked site (very common) then it may have a injected script to download malware or exploit a specific browser, etc. the web shield is very hot on these types of attack. You could also be redirected to a malicious site and the web shield is good at preventing that as is the network shield.
Prevention is by far better than cure, the web shield prevents it getting on to the browser cache, it is also scanning more files by default it scans all files/archives, etc. It can through its prevention of exploits and hacked sites prevent the redirection to a malicious site which could download a piece of malware unknown to the file system shield.
I don’t have the P2P or IM Shields installed as I don’t use any P2P or IM applications.
To allow different sensibility and configurations. You can make your security harder in critical points and allow more resources when in common situations.
You can use the default settings that are the best balance between performance and security.