Automatic software threat updating
The application of security patches commonly occurs in this manner.
The size of patches may vary from a few bytes to hundreds of megabytes; thus, more significant changes imply a larger size, though this also depends on whether the patch includes entire files or only the changed portion(s) of files.
Some programs can update themselves via the Internet with very little or no intervention on the part of users.
Microsoft Windows NT and its successors (including Windows 2000, Windows XP, Windows Vista and Windows 7) use the "service pack" terminology.