A web filter appliance is a device that allows the user to filter all online content for censorship purposes, such that any links, downloads, and email containing offensive materials or pornography is outright blocked or removed. These appliances can also help you prevent malware infection because, more often than not, malware is usually hidden within links that promise porn or controversial content. Moreover, because the number of online hazards is unstoppably increasing every day, it's always prudent to get a web filter appliance that can adapt to the changing times and the ever-evolving hazards posed by the Internet.
The best web filtering gadgets available are those that support a UTM (Unified Threat Management) architecture or are at least considered "future proof" (that is, they have regularly updated modules that will remain compatible to future platform releases without any major alterations to their software setups) enough to guarantee protection for both known and future websites. However, as the flood of new threats continue to emerge through the bowels of the information superhighway, these virtual contagions' complexity will most likely improve in conjunction with their numbers as well, which should make most traditional online filters outdated and obsolete in just half a year of operation, or maybe even sooner than that.
At any rate, content filtering appliances have a distinct advantage over their software counterparts in terms of stable restriction features, unrestricted monitoring, no platform-based limitations, easy upgrades and improvements, and so on. That's because the best web filters are fully integrated software and hardware systems that optimize their hybrid attributes when it comes to content filtering by gaining full, unmitigated control over online usage through well-defined policies as mandated by the owner of the network or the IT security administrator.
Getting a filter that has a list of premium-grade and detailed content analysis with predefined categories (which includes keywords for pornography, game downloads, drugs, violence, adult content, offensive content, racist content, controversial content, and the like) is a must for any major network. All of the items you'll ever need to block should be easily selectable with a click of your mouse as well; after all, sophisticated technology aside, a good web filter appliance should also be intuitive and practical to use as well.