A "Browser Helper Object" is a
DLL that allows developers to customize and
control Internet Explorer. When Internet Explorer starts it reads the
registry
to locate any installed BHOs and then creates them. Created BHO's have access to
all the events and properties of that browsing session. Every time a new browser
window is opened, it creates a copy of the BHO and when that window is closed,
it destroys its copy of the BHO.
