If you own a more advanced camera then you can save your image in .RAW or .JPG format. Both do have their advantages and disadvantages.
Advantages of .raw (in comparison with jpg)
- It contains more colour and brightness information. It can make differences between “dark dark dark dark” and “dark dark dark”. (JPG can distinguish between 256 levels of brightness, RAW between 4,096 – 16,384!)
- All the information that sensor collects get into the .raw file. That gives the possibilty to edit the pictures in for example Lightroom much better than .jpg would do it.
- Over-/ underexposed pictures can be better fixed, due to the amount of information saved in the brightness
- White balance can be better adjusted
- Noise reduction in Lightroom is very powerful in case you have a noisy picture (due to high ISO for example)
- When you do some colour changes, the original file will not altered
- A finer grading of colours and tones is possible (because more information is saved)
Disadvantages of .raw (in comparison with .jpg)
- A .raw file needs mostly 20-30MB (by a 20MP picture), a .jpg 8-12MB (by a 20MP picture). So you need a hell of storage space to save them!
- To save all your changes you need to export them as .jpg – that may take some time.
- You cannot save so fast pictures in .raw than in .jpg, and the camera buffer gets faster full.
- A .raw file is not all the time the same. A .raw file from Nikon, Samsung, Canon etc. is different, you need a decoder – or lightroom needs a decoder. Thats why with new cameras you need to update Lightroom.
- You need an special editor, Lightroom is not for free (but expensive cameras do come with Lightroom), to view .raw – the standard windows explorer is not able to show .raw.
Not sure which format to shoot? Here I have an example between a JPG & RAW picture and make your own opinion đ

18 mm | ISO 100 | f.8.0 | 1/400s | Samsung NX300M – 10,4MB
Island Usedom Forest, Germany
Original JPG File – no editing applied
And now the direct comparison: