ConsoleKit is a system daemon for tracking what users are logged into the system and how they interact with the computer (e.g. which keyboard and mouse they use). This is used by Fedora - Fast User Switching. Leave this enabled if you plan on using this feature.
NetworkManager is daemon meant to automate switching between network connections. Many laptop users who switch between Wireless WiFi connections and/or Ethernet connections may find this useful. Most stationary computers should have this disabled. Some DHCP users may require this.
Advanced Configuration and Power Interface daemon which controls and allows interfacing to power management and certain input devices. This is not installed by default in Fedora 7. It is recommended to be enabled only if you need it.
anacron, atd, cron
These are schedulers with each having slightly different purposes. It is recommended you keep the general purpose scheduler cron enabled, especially if you keep your computer running for long periods of time. If you are running a server look into which schedulers you require. Most likely atd and anacron should be disabled for desktops/laptops. Please note that some sheduled tasks such as cleaning /tmp or /var may require specific schedulers.
This saves audit records generated by the kernel. This information can be used in different ways. SELinux uses the audit daemon to record events. While there are other logging services it is recommended you leave this enabled (especially for users with SELinux enabled). Some information on how to utilize audit can be found on RH Magazine.
This mounts removable disks (such as USB harddrives) on demand. It is recommended to keep this enabled if you use removable media.
Avahi is an implementation of zeroconf and is useful for detecting devices and services on local network without a DNS server. This is also the same as mDNS. Most likely this is unnecessary unless you have compatible devices/services. I have this disabled.
bluetooth, hcid, hidd, sdpd, dund, pand
Bluetooth is for portable local wireless devices (NOT wifi,802.11). Some laptops come with bluetooth support. There are bluetooth mice, headsets and cell phone accessories. Most people do not have bluetooth support or devices, and should disable this. Other services with bluetooth: hcid manages all devices, hidd provides support for input devices (keyboard, mouse), dund supports dialup networking over bluetooth, pand allows connections to ethernet networks over bluetooth.
These services support the automatic seeding and tracking for torrents used by the peer-to-peer networking system BitTorrent. These should be disabled unless you specifically wish to seed or track torrents. By seeding you are essentially sharing the contents of the torrent with others and by tracking you are coordinate the action of other BitTorrent clients. More information from a BitTorrent FAQ. Keep in mind these require network bandwidth and other configuration as well.
For users with ISDN hardware only. Should be disabled for most users.
This throttles your CPU runtime frequency to save power. Many modern laptop CPU's support this feature and now many desktops also support this. Most people should enable only if they are users of Pentium-M, Centrino, AMD PowerNow, Transmetta, Intel SpeedStep, Athlon-64, Athlon-X2, Intel Core 2 hardware. Disable this if you want your CPU to remain at a fixed state.
Used for printing. These should be enabled only if you have CUPS compatible printer that works in Fedora.
Distcache is for distributed session caching. It is primarily for SSL/TLS servers. Apache can use this. Most desktop users should have these disabled.
This basically an interface for the D-BUS system to control networking devices on your computer. It is highly recommended you leave this enabled if you are using NetworkManager, use DHCP, are on a Laptop or require switching between different networks (ie. wired, unwired). Fixed IP or users who don't use DHCP to connect to their network can disable this.
This service is specific to Fedora's installation process meant to perform certain tasks that should only be executed once upon booting after installation. Even though it verifies it has been run before (using /etc/sysconfig/firstboot), it can be disabled.
This is the console mouse pointer (no graphics). If you do not use the text console (CTRL-ALT-F1,F2..) then disable this. However it is good practice to leave this enabled for runlevel 3 (console) and disabled for runlevel 5 (x-server).
HAL refers to the Hardware Abstraction Layer. This is a critical service for collecting and maintaing information about hardware from several sources. Fedora requires this, hence leave this enabled. Read for an overview of HAL.
hplip, hpiod, hpssd
HPLIP is a service to support HP printers in Linux, including Inkjet, DeskJet, OfficeJet, Photosmart, Business Inkjet and some LaserJet printers. This supported by HP through HP Linux Printing Project. HPLIP should be enabled only if you have a supported compatible printer.
This is the Apache HTTP Web Server. If you installed this and are doing web development then leave this enabled. However most desktop users and/or non-developers should leave this disabled.
This is the standard Linux software firewall. This is highly recommended if you are directly connected to internet (cable, DSL, T1). It is not required if you use a hardware firewall (D-Link, Netgear, Linksys, etc) but it is still recommended.
This services is the firewall for IPv6 communication. If you are not using IPv6 (most users), then you can disable this.
IrDA support infrared communications between devices (laptops, PDA's, mobile phones, calculators, etc). This should be disabled for most users.
This service is to increase performance across processors on a multiprocessor system. For users who do not have multiple processors/multiple cores this should be disabled. However newer computers with multi-core CPU's (Intel Core 2 Duo, AMD X2) should enable this. Leaving this enabled will not effect performance on single CPU/single core systems.
This is another form of internet connect service/hardware. Unless you have an ISDN modem, disable this.
Kudzu is Fedora's hardware probing service. It optionally configures changed hardware. If you swap hardware or need to detect/re-detect hardware this can be left enabled. However most desktop or servers can disable this and run it only when necessary.
LIRC provides support for infrared remote controls in Linux. If you do not have this hardware, leave this disabled. However this is required for infrared control in applications such as Myth TV.
LISa is LAN information service and provides similar functionality to the "network neighbourhood" concept in Windows. While this is only useful for computers on a network, users of Samba or NFS may not require this. Most users should leave this disabled.
lm_sensors provides monitoring for motherboard sensor values or specific hardware (commonly used with laptops or high-end servers). It is useful for watching realtime values for PC health, etc. This is also popular with GKrellM users. It is recommended to disable this unless you have a need.
This is required to see proper context information when you are using SELinux. By default, Fedora has SELinux enabled. Users who do not use SELinux can disable this.
Is useful for monitoring Software RAID or LVM information. It is not a critical service and may be disabled.
This is an IPC (Interprocess Communication) service for Linux. Specifically this communicates with D-BUS, a critical component. It is highly recommended to leave this enabled.
The Network Audio System is a network transparent, client/server audio transport system. It can be described as the audio equivalent of an X server. This is connected into the KDE sound system. This should be left enabled.
Initializes network console logging. This can be left to its default disabled state.
This is used for automatic mounting of any shared network file space such as NFS, Samba, etc on bootup. Useful if you connect to another server or filesharing on your local network. Most single desktop/laptop users should have this disabled.
Netplugd can monitor network interfaces and executes commands when their state changes. This can be left to default disabled.
This the standard network file sharing for Unix/Linux/BSD style operating systems. Unless you require to share data in this manner, disable this.
This is used by Samba. Please see Samba.
This daemon handles passwords and caches them for naming/authentication services like NIS, NIS+, LDAP, or hesiod. This should be disabled.
This automatically updates the system time from the internet. Mentioned in the installation process. If you have an active ("always-on") internet connection it is recommended you enable this, but it is not required.
Provides support for Smart Cards and Smart Card Readers. This are small chip like devices that are embedded in certain credit cards, identification cards, etc. Unless you have such a reader, this should be disabled.
This services is to improve startup performance by preloading certain applications into memory. If you wish to startup faster leave this enabled.
Is used to monitor and restore proper file contexts for SELinux. This is nNOT required but highly recommended if you use SELinux.
This manages remote procedure call support for other services (such as NFS or NIS). This is similar to 'portmap'. This can be disabled if you have no other services depend on it.
rpcgssd, rpcidmapd, rpcsvcgssd
Used for NFS v4. Unless you require or use NFS v4, these should be disabled.
Unless you run a server or you like to transfer or support a locally shared IMAP or POP3 service, most people do NOT need a mail transport agent. If you check your mail on the web (hotmail/yahoo/gmail) or you use a mail program such as Thunderbird, Kmail, Evolution, etc. then you should disable this.
This is the SELinux Troubleshooting Daemon. This services provides information to the setroubleshoot Browser. This application provides notices on the desktop if there were SELinux problems (usually AVC denials. While this is not a critical service it is incredibly helpful for debuggin SELinux issues. Leave this enabled only if you have SELinux enabled.
The SMART Disk Monitoring Daemon can be used to monitor and predict disk failure or problems on hard disk that support this. Most desktop users may not need this unless there is possible problems, but is it recommend to be left enabled (especially for servers).
The SAMBA daemon is required to share files from Linux to Windows. This should be enabled only if you have windows computers that require file access to Linux. There is information on configuring Samba for Fedora 7.
This daemon provides monthly information for Smolt which is gather statistics and information to assist Fedora developers. Statistics are available. Users who wish to help and share information should enable this, otherwise leave this disabled.
SSH allows other users to log into or run applications on your computer from another computer on your network or remotely. This is a potential security issue. This is not needed if you have no other computers or no need to login from a remote location (work, school, etc.). Most likely this should be disabled.
The YUM Update notifier daemon provides notification of updates which are available to be installed to your computer. If you do NOT have an active ("always-on") internet connection leave this disabled. Some updates are for security and many are for bug fixes and or newer software versions. Please understand that continuous updating with yum may lead to many problems.