Many people use Internet Explorer everyday as their primary browser because it comes pre-installed with their home PC, but doing so poses a significant threat if you are not a sophisticated computer user.
It's easy to understand why if you know some history about the browser wars.
In 1,995 Netscape grew extremely fast and in a very short time gained almost 90% market share waking up the giant Microsoft that started rapid improvements in his own browser making version after version almost every year.
Suddenly, once Internet Explorer became the dominant browser, Microsoft stopped new developments.
Although Microsoft Internet Explorer is the dominant browser with more than 85% market share, Firefox is steadily gaining ground because of its many features and greater security.
Internet Explorer was designed very fast to take Netscape out of the market, but in the process to add features his security was left behind.
Firefox can help you protect from very serious threats like: viruses, spyware and other malware because it's harder for this malware to get through your browser and get installed in your PC.
Although Firefox is more secure than Internet Explorer, all computer users should also have a personal firewall, antivirus software and a spyware cleaner.
Also, some knowledge about general security could help minimize your exposure.