I want to create a database in Sqlite from Visual Studio with C # but I want to know if creating the software (.exe) when creating the program only creates the executable or an external file such as a dll file ? , what I want to know is if the final result will be the executable alone or if it will contain other files that depend on it.
When you create a program in .Net the program is a .exe or a .dll only, when adding third-party libraries or when referring to others libraries then you will have to install the .exe and the .dll of the libraries that you need for your program to work as the libraries could be to use SQLite.Net.
There are tools like ILMerge that allow you to create a .exe that contains your .exe and all the .dll libraries that you need and thus you would have a single .exe.
Now for your particular case, the sqlite database may not exist at the time you install the application but sooner or later your program will have to create the sqlite file somewhere outside of your .exe.
The result or product of your application depends on how the solution is built. A solution in Visual Studio can contain one or more projects and each project generates a compiled assembly that can be (primarily) an EXE file or a DLL.
For example, if the entire access layer to your database is generated in a separate assembly or project, this project will compile a DLL library that can be linked from your main project (which could be a user interface with windows) for data manipulation) and use the public services of the same library.
In addition to the above, projects usually integrate references (for example, database access libraries, collections of controls, property classes or helpers , etc. ) and that will also be included (if configured) in the final output of the project.
The decision to design the solution is made by the programmer: the development environment (Visual Studio) presents certain conventions to be followed by the platform or framework .NET, but the application builds it as wish Obviously you can use arquitectonicos patrones to facilitate the construction of your solution, but that is also Your decision.