I think there is almost no difference. The whole question is how much it costs and what quality it is. What guarantees they give. This should be studied. Read the contract for the provision of services. Then you can conclude what is better and what is worse.

The decision you make will depend on many factors and, above all, what the software is intended for as a final objective, but in short, if you decide to develop the software internally, all the work will be in your own company and whether the software does well or badly will be your responsibility. from you, on the other hand, if the software is developed externally, you can receive external help in this way. If there is an error, the solution will be sought by both your company and the developers outside your company who have collaborated, but if you still do not understand or have If you have any doubts, you can read this article where it perfectly details each one of the points, the pros and cons of external and internal

I think it's better to contact a professional programmer who will help you in this matter. Such people understand more and know how they can help you. After all, this question is very close, there are factors that need to be learned from you in more detail.