Several ways to enter insert mode in VIM

Enter into input mode in command-line mode to tap I, A, O, S, I, A, O, S

The difference between them makes a memo:

• I: Start insertion at the cursor position match either
• A: Start inserting in the word specifier the cursor
• o: Insert a new row below the line where the cursor is located
• S: Delete the character of the cursor and start inserting

• I: Inserted at the beginning of the line where the cursor is located, if there is a space at the beginning of a space
• A: Start inserting at the end of the line where your cursor is located
• O: Insert a line starting at the top of the row where the cursor is located
• S: Delete the cursor line and start inserting

In addition u undo previous Action Ctrl+r restore previous undo action

Several ways to enter insert mode in VIM