軟體更新和升級有什麼區別？

有人說“更新”是小改動，“升級”是大改動。我對軟體更新和升級感到非常困惑。什麼時候應該使用更新與什麼時候應該使用升級。

有人可以解釋包管理器中這些術語之間的區別嗎？

Ubuntu / Debian等使用apt-get：

你應該先執行update，然後upgrade。它們都不會自動執行另一個。

• apt-get update更新可用軟體包列表及其版本，但不安裝或升級任何軟體包。
• apt-get upgrade實際上會安裝您擁有的軟體包的較新版本。更新列表後，包管理器會知道您已安裝軟體的可用更新。這就是為什麼你首先想要update.

-來源。

但是對於使用yum的Red Hat / CentOS ，該命令會詢問您是否要應用它找到的更新。update

$ sudo 百勝更新

獲取所有可用更新的列表並詢問您是否要應用它們。像這樣：

[..] 
kf5-sonnet-core                            x86_64                   5.33.0-1.el7                                    epel                   150 k
kf5-sonnet-ui                              x86_64                   5.33.0-1.el7                                    epel                   141 k

Transaction Summary
==================================================================================================================================================
Upgrade  52 Packages

Total size: 15 M
Is this ok [y/d/N]: 

當您的朋友將update稱為“小改動”而將 upgrade稱為“大改動”時，他實際上是指upgrade和dist-upgrade之間的區別。

從 apt-get 手冊：

  upgrade
      upgrade is used to install the newest versions of all packages
      currently installed on the system from the sources enumerated in
      /etc/apt/sources.list. Packages currently installed with new
      versions available are retrieved and upgraded; under no
      circumstances are currently installed packages removed, or packages
      not already installed retrieved and installed. New versions of
      currently installed packages that cannot be upgraded without
      changing the install status of another package will be left at
      their current version. An update must be performed first so that
      apt-get knows that new versions of packages are available.

  dist-upgrade
      dist-upgrade in addition to performing the function of upgrade,
      also intelligently handles changing dependencies with new versions
      of packages; apt-get has a "smart" conflict resolution system, and
      it will attempt to upgrade the most important packages at the
      expense of less important ones if necessary. The dist-upgrade
      command may therefore remove some packages. The
      /etc/apt/sources.list file contains a list of locations from which
      to retrieve desired package files. See also apt_preferences(5) for
      a mechanism for overriding the general settings for individual
      packages.

引用自：https://unix.stackexchange.com/questions/361814