Deleting

x delete character under cursor

dd delete line under cursor – delete entire current line

dw delete word under cursor

db delete word before cursor
Nx delete N characters, starting with character under cursor

dNw delete N words beginning with character under cursor; e.g., d5w deletes 5 words

D delete the remainder of the line, starting with current cursor position

Ndd or dNd delete N lines, beginning with the current line; e.g., 5dd deletes 5 lines