yast online update - what does "patch reinstall" mean?

When I run “online update” in yast (in text mode), some of the patches are marked with “>”. According to Help, it means:

>: The patch will be reinstalled.

What’s the purpose of it? I didn’t see anything similar in any other distribution, when it comes to system updates.

In the desktop open a terminal and become su, then do

zypper ref

then

zypper up

that should sort out your updates.

Thanks, I’m new to SuSE, didn’t know this tool.

It offers me a different set of updates than yast. For example, with yast, I updated all packages but kernel; zypper offers more packages.
What will happen here (below)? Will This SLES SP1 be updated to SLES SP2?

sudo zypper up
Restoring system sources…
Parsing metadata for SUSE Linux Enterprise Server 10 SP1…
Parsing metadata for SLES10-SP1-Updates…
Parsing RPM database…
Summary:
<install> [S2:0][product]SUSE-Linux-Enterprise-Server-SP2-migration-10-24.i386
<install> [S2:0][patch]slesp1-kernel-5566-0.noarch
<install> [S2:0][patch]move-to-sles10-sp2-0-26.noarch
<install> [S2:0][atom]kernel-bigsmp-2.6.16.54-0.2.10.i586
<install> [S2:0][atom]kernel-bigsmp-2.6.16.54-0.2.8.i586
<install> [S2:0][script]move-to-sles10-sp2-script.sh-0-26.noarch
<install> [S2:0][atom]kernel-bigsmp-2.6.16.54-0.2.12.i586
<install> [S2:0][message]move-to-sles10-sp2-message-0-26.noarch
<install> [S2:0][patch]slesp1-kernel-5375-0.noarch
<install> [S2:0][package]kernel-bigsmp-2.6.16.54-0.2.12.i586
<install> [S2:0][patch]slesp1-kernel-5734-0.noarch
<uninstall> [S0:0][package]kernel-bigsmp-2.6.16.54-0.2.5.i586
Continue? [y/n]:

Hang on. This is the openSUSE forum. You need
SLES: SUSE Linux Enterprise Server (SLES) - NOVELL FORUMS

Better check there