This CS50 lecture delves into fundamental concepts of memory management and pointers in C. It covers how data like images are represented, introduces hexadecimal notation for memory addresses, and explains the crucial role of pointers for direct memory access using operators like `&` and `*`. The video demonstrates dynamic memory allocation with `malloc` and `free`, highlights the dangers of uninitialized pointers and buffer overflows (including a real-world incident), and clarifies the difference between pass-by-value and pass-by-reference in functions. Finally, it explores file I/O operations in C, setting the stage for image manipulation in problem sets.