PeLib is an open source C++ library with the purpose to ease the access and modification of PE (Portable executable) files. This is done through a multitude of classes which represent all important PE header and directory structures and which provide the necessary functions to read, modify and write these structures.
The section header
The section header is stored after the OptionalHeader structure in the PE header. Microsoft provides the macro IMAGE_FIRST_SECTION to get the start address based on the PE header.
The PE header
The PE header contains informations about the different sections inside the executable that are used to store code and data or to define imports from other libraries or exports this libraries provides.