Exactly. Internally, the data structure serialized as "LLVM bitcode" (or the textual equivalent) is a list of functions, each function represented by a Control

Exactly. Internally, the data structure serialized as "LLVM bitcode" (or the textual equivalent) is a list of functions, each function represented by a Control Flow Graph of basic blocks. Each basic block contains runs of SSA (static single assignment) instructions without jumps and flow control (effectively a DAG of operations). There is also some basic data structure layout information. This representation is very handy for code generation, code analysis, and implementing optimization passes.