Whenever we write a C# code and build or run the solution it generates 2 folders −

- bin

- obj

These bins and obj has the compiled code

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Why do we have 2 folders?

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The reason is the compilation process goes through 2 steps

- compiling

- linking

In the compiling every individual file is compiled into individual units

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These compiled files will be later linked into one unit which can be a dll or an exe

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Whatever happens in the compiled phase will be added into obj folder

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The final compilation that is the linked phase will go into bin folder

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This obj folder is used in Conditional compilation or incremental compilation

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Ex − I have a big project and it has multiple solution and multiple files

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suppose if I change any one of the files and build the solution then only that file will be compiled this information will be present in the obj folder