Portable Executable (PE) file headers are a special type of data structure found in executable and object code files that allow Windows operating systems to load, link, and run the functionality of the executable. PE files are the native format for executables, dynamic link libraries (DLLs), and object files created for Windows systems.
The PE format consists of several parts, each designed to support a certain purpose. The header, which is the first part of a PE file, is used to manage the resource layout of the image and to identify the other components of the file. It also stores important information about the target architecture and file type.
The header contains several fixed-size data fields that provide information about the file’s size and checksum. It has fields such as File Alignment, Number of Data Directory Entries, and Flags, which tell a program how to accept the information supplied. This header also holds the entry point which specifies where the program will start executing the instructions contained in the PE file.
The header also contains several optional, variable-length data fields, such as the Export Table, the Import Table, the Resource Directory Table, the Debug Table, and the Security Table. These components are necessary for loading the contents of the image correctly.
PE files are used as native file formats for compiled programs, such as device drivers, services, applications, and dynamic link library (DLL) files. It is an important part of the Windows operating system, and as such, it is responsible for keeping track of executable code, DLLs, memory management, and other system functions. This makes it essential for anyone who is programming for Windows.
