What are the main differences between gestalt therapy and cognitive behavioral therapy? Can someone explain the main differences in an easy to understand way between gestalt therapy and cognitive behavioral therapy? 

Which is better suitable in which situations? I read some articles online but I still don't have a clear picture.
In a very elementary and basic way Cognitive Behavioral Therapy focuses on mental schemas and behavior modification techniques.

https://en.wikipedia.org/wiki/Schema_(psychology)

https://en.wikipedia.org/wiki/Cognitive_behavioral_therapy

In the formulation of the case the professional analyzes how attitudes, behavioral dispositions, behavior and the interpretations of all this are related to the different problems and disorders.

You can find numerous information about this so I will try some differentiations of Gestalt therapy.

I would emphasize first that Gestalt therapy maintains a greater link with therapies close to emotions or where a therapy must have special consideration of emotional processes, this feature is easy to see at first, and in his theory some develop principles to analyze emotions, his theory considers what, how, why of those emotions, in this way become important goals and objectives that represent important factors of emotional and behavioral change.

Some features commented very briefly:


Awareness and responsibility (initially could be considered similar to locus of control): The immediate holistic experience is considered, this means that are considered perceptions, sensations, feelings, thoughts and wishes or intentions, it is about going a little further beyond simple words or superficial conversations, it is about what the person thinks and does but also about what they feel, how they perceive certain situations or how they interpret them.
Concept of self (this theory of Rogers is well known: self-worth, self-image, ideal-self) considering a holistic perspective or integrated cognitive but emotional, motivational and relational or social system, which perceives, evaluates, experiences and that is related to behavioral tendencies and manifest behavior about the environment. For example, not only what is done but what is wanted to do or intentions or make small changes to the behavior are considered.
The attention to the present moment is prioritized, the professional and the client during the sessions work in a direct way with the problems, not with the words about the problem, that is, in therapy they working all the aspects involved in the problem while the problem manifests.
A therapeutic relationship style close to Client-Centered Therapy, for example working from a style where the professional only directs to the client in front of a style of authoritarian expert.


Finally, it is very important to highlight the evidences of Gestalt Therapy that are sometimes ignored as in the case of humanistic-experiential therapies and there is also an important publication bias, one of the most important documents from which follow the evidences of this therapy is this chapter released or freely accessible:

https://core.ac.uk/download/pdf/110659465.pdf

Elliott, R., Watson, J., Greenberg, L.S., Timulak, L., &amp; Freire, E. (2013). Research on humanistic-experiential psychotherapies. In M.J. Lambert, Bergin &amp; Garfield's Handbook of psychotherapy and behavior change (pp. 495-538). New York: Wiley.