MySQL Server Administration - Mastering phpMyAdmin 3.1 for Effective MySQL Management - page 275

Here, reload the privileges is clickable. The effective privileges (the ones against
which the server bases its access decisions) are the privileges that are located in
the server's memory. Privilege modifications, to be made from the User overview
page, are made both in memory and on disk, in the mysql database. Modifications
made directly to the mysql database do not have immediate effect. The reload the
privileges operation reads the privileges from the database and makes them effective
in memory.
Adding a user
The Add a new User link brings a dialog for user account creation. First, we see the
panel where we'll describe the account itself.
The second part of the Add a new User dialog is where we'll specify this
user's global privileges, which apply to the server as a whole (see the Global
privileges section).