Vim's visual mode provides flexible text selection and manipulation. Three visual modes: v for character-wise visual mode, selecting character by character; V for line-wise visual mode, selecting line by line; Ctrl+v for block-wise visual mode, selecting rectangular blocks. Operation commands: In visual mode, d to delete selected content, y to copy selected content, c to change selected content, u to convert to lowercase, U to convert to uppercase, ~ to toggle case, > to increase indent, < to decrease indent, gU to convert to uppercase, gu to convert to lowercase. Block-wise visual mode is particularly powerful, allowing simultaneous editing of multiple lines at the same position, such as batch adding comments, modifying multiple variable names, etc. Press Esc to exit visual mode. Visual mode combined with other Vim commands enables complex text editing tasks and is an important tool for efficient Vim editing.