Separate the address from its contents
The left column identifies a storage location. The pairs of hexadecimal digits in the middle are bytes read from that location, and the ASCII column is another interpretation of those same bytes. Both addresses and contents look like numbers, but a location containing a value is different from that value pointing somewhere else. DBG Desk reads 256 bytes and displays 16 bytes per row. The next row starts 16 bytes later. These row boundaries are a display choice, not necessarily the boundaries of a structure or allocation.
Check size and byte order
On typical x86 targets, the 32-bit integer 0x12345678 appears in memory as 78 56 34 12 at increasing addresses. Reading the bytes from left to right is therefore not the same as reading a conventional integer notation. Signedness changes interpretation too. Do not treat every group of bytes as a pointer. Check the source declaration and the operand size of the instruction reading or writing the value. Without size and type information, a plausible-looking number can lead you to an unrelated location.
The text column is only a partial view
A dot in the ASCII column does not mean that memory is empty. DBG Desk uses dots for bytes outside the printable ASCII range. Zero bytes, line breaks, and parts of UTF-8 Korean text can all appear that way. Check the encoding and termination rule before declaring a string truncated. A C string usually ends with a zero byte, while another buffer may use a separate length. A string object can also contain pointers and bookkeeping before its character data. Opening the object address does not necessarily show its first character.
Understand what a failed read tells you
An unreadable address can be unmapped, protected, taken from another run, or based on a value incorrectly interpreted as a pointer. A 256-byte request may also cross the end of a readable region. Conversely, readable memory does not prove that an object is still alive; freed storage can remain readable. Interpret the bytes together with allocation and release events and the current execution point. A snapshot is evidence about stored bytes, not an automatic validity check.
Practice with a known value
Store 0x12345678 in a small integer and stop after the store. Compare the layout with a build that stores 0x12345679. Predict the changed byte before checking the display. Find the current storage location again in each run instead of expecting an identical address. Once the byte order makes sense, move to structures while accounting for field sizes and padding.
value: 0x12345678
bytes: 78 56 34 12