Internet Explorer, often referred to simply as IE, is a product of the Microsoft corporation, it comes as standard with all Windows operating system and specially used by those who are not too versed in computers and take all of the default options offered by their operating system.
You can use CTRL+SHIFT+P to activate Internet Explorer InPrivate browsing mode or go to Settings>Safety>InPrivate browsing, this feature will make the browser run in RAM and it will not store your Internet browsing story, cookies or cache, when you close the browser everything should be gone. It provides medium security, it is a good idea to use privacy mode if you share computer with someone else at home or are using an Internet cafe or library, the main vulnerability of inPrivate browsing mode is the possibility that there is a computer crash while you surf the Internet, if that happens the browsing story held in RAM will be dump to a Windows temporary file that can later on be recovered with specialist tools.
If you are on a public computer you should always consider the environment non safe, it is impossible to know for sure what kind of monitoring tool has been installed by the network administrator, nevertheless, it is still a good idea to use your Internet browser privacy mode, it will make surveillance gathering much more difficult, if you can run a portable Internet browser from inside a USB thumbdrive even better, but there is no Internet Explorer portable version you will have to use Firefox for that.
The widespread use of Internet Explorer, included with all Windows operating system, makes it a high target for malicious hackers and spyware, Microsoft doesn't have the best record of timely patching up known security vulnerabilities and there are very few privacy addons for this browser, good alternatives are Firefox, Opera or Chrome.