For a true professional photographer, you will always need to edit or process your photos in order to improve them. There is several software available, and perhaps the most popular on is Adobe Photoshop (PS). I will explain the pros and cons of PS here:
Pros of the software
- There are a lot of design tools
- High level of control
- Useful for photo corrections, and this is what you want as a professional photographer
Cons of the software
- It costs you a lot
- The interface can be very difficult to understand
- Touch and stylus inputs pretty hard to use