I share your confusion about those many sources of drag.

In the end, many of them describe similar things. When doing a performance calculation, it is extremely important to add all drag sources and to do this for every one only once. Drag estimation requires meticulous [bookkeeping][1]. Therefore, I would distinguish only two types of drag:

 1. Viscous drag, where the flow is slowed down by friction. The result is a force parallel to the local surface, and viscous drag is its component parallel to the flow direction at infinity.
 2. Pressure drag, where the local lift vector is tilted away from the vertical (in reference to the flow direction at infinity).

Profile drag is a muddle because it adds both types, but only part of them. This makes proper bookkeeping harder. As Trebia Project writes, profile drag is the drag in 2D flow and neglects both interference and lift-related components. But when designing an aircraft, profile drag is easy to get at - [just look it up][2] or run a [calculation][3].

Profile drag includes the full [friction component][4] of the unswept wing without engine and real-world effects (so no drag from flap gaps, pylons, flap track fairings, rivet heads ...), the [pressure drag][5] from incomplete pressure recovery and [wave drag][6] in supersonic flow. It excludes the lift-related drag (induced drag) in subsonic flow, the pressure drag stemming from interference and the drag increase in the slipstream of a propeller. All these drag sources need to be added and be kept free of drag that was already considered in the profile drag data.


  [1]: https://aviation.stackexchange.com/questions/23380/how-can-one-quickly-estimate-interference-drag-for-a-configuration/23384#23384
  [2]: http://m-selig.ae.illinois.edu/ads/coord_database.html
  [3]: https://aviation.stackexchange.com/questions/544/how-to-go-about-designing-a-custom-airfoil
  [4]: https://aviation.stackexchange.com/questions/16953/how-do-insects-decrease-aircraft-performance/16956#16956
  [5]: https://aviation.stackexchange.com/questions/5048/why-does-supersonic-flight-detach-airflow-from-a-wing/5055#5055
  [6]: https://aviation.stackexchange.com/questions/25089/why-is-the-coefficient-of-drag-for-straight-wings-at-supersonic-speeds-lower-tha/26555#26555