The presence of a blue dot adjacent to a conversation thread within the Android Messages application signifies that the message or messages within that thread have not yet been opened and read by the user. This serves as a visual indicator of unread communication. It disappears once the user accesses the conversation and the messages are viewed.
This visual cue enhances user experience by providing immediate awareness of pending messages. It streamlines communication management, preventing users from overlooking important or time-sensitive information. Functionality of this nature has become a standard feature in modern messaging platforms, improving efficiency and ensuring prompt responses.