I'm writing an Internet Explorer addon, and currently I need to have two separate components, one of which shows up as a "Browser Extension" and the other as a "Browser Helper Object" in the Manage Add-ons screen of Internet Explorer.
It's not clear to me why I need both of these, or what the difference is.
Brower extensions appear in the IE interface; think toolbar buttons, panels in the window frame, and so on. To add a command to the right-click shortcut menu, you would create a browser extension.
Browser helper objects (BHOs) extended IE services. (Flash and Silverlight were implemented as BHOs.) If you want create a capability for IE, you'd create a BHO.
Um, you know that IE's no longer in active development, right? It's been replaced by Microsoft Edge. There may be little value in creating an add-on using IE's proprietary interfaces and services.
As of Win 10 Anniversary update, Edge supports extensions created for other browsers. It's also much easier to create extensions for Edge.
It might be easier, in the long run, to shift to Edge or another browser (if you can't/won't run Win10).