Upgrade and Update interchangeable?

[RanYanivHartstein]

In 3.0, upgrade and update are used seemingly interchangeably, for themes, plugins and core. This can lead to unnecessary confusion - in some cases, the two terms are used to describe the same thing.

In #4868, it's stated that "update" should generally be used to refer to "new versions". This was, apparently, to differentiate between *updating* to a new version and then *upgrading* the database.

However, this is no longer "enforced" in 3.0.

For example, for plugins and themes, I might see "3 upgrades available", but when I want to run the update/upgrade, I need to click "Update Plugins". After that, I may get this error: "Plugin upgrade failed".

This is just a quick example to demonstrate the issue. There are more instances of upgrade/update across the UI. I can give a more detailed list or just provide a patch.

My suggestion is to revisit the original conclusion of #4868, and decide again which term should be used when updating/upgrading either core, plugins or themes.

Personally, I vote for "upgrade":

Most users won't understand the difference between updating their files and upgrading the DB schema (which is probably one of the reasons automatic update was added in the first place). The way developers treat it in the code shouldn't necessarily be reflected in the UI. To users, it would make more sense to treat these two actions as two stages in the upgrade process, instead of two separate processes.

This thinking can inform other changes in the upgrade process, or just lead to a more uniform use of upgrade/update. Either way, the current state of things is confusing.

[nacin]

We should be standardizing on the word 'update'.

[latz]

Should only be the output be standardized to "update" or even all file, class, variable, function, and method names in the source code?

[latz]

The above patch changes all output strings containing "upgrade" to "update".

[markjaquith]

(In [16696]) Standardize around "Update" instead of "Upgrade." props RanYanivHartstein. props latz. fixes #14107

[SergeyBiryukov]

There's a misprint in wp-admin/upgrade.php on line 68: “You cannot udate”.

[nacin]

(In [16823]) Fix typo. props SergeyBiryukov, fixes #14107.