Definition of Data structure alignment

Data Structure Alignment is the way data is arranged and accessed in computer memory. It consists of two separate but related issues: Data Alignment and Data Structure Padding. Data Alignment is the offset of a particular datum in computer memory from boundaries that depend on the datum type and processor characteristics. Aligning data usually refers to allocating memory addresses for data such that each primitive datum is assigned a memory address that is a multiple of its size. Data Structure Padding is the insertion of unnamed members in a data structure to preserve the relative alignment of the structure members.