Cydia is basically an AppStore that gets its fuel from the large iPhone Jailbreak Community. Cydia is where you will find all the 3rd party Apps, Themes, Tweaks, Mods, Add ons that you can not find on Apple’s AppStore.

How do i get Cydia? – Cydia is Installed on the iPhone/iPod Touch when you JailBreak your Device. [JailBreak Guides]

Cydia Home : Cydia Home is where you will find some useful Info & links to Packages.

Featured Apps : Featured Apps are ones — That are available via Cydia (You will find this section useful)

Sections – Sections are categories – Here you can find what you are looking for easily.

Changes (Updates & New Stuff) – If a package that you have is updated it will be listed here. Whenever there is a new package the new packages are shown under this section as well by date.

Manage (Add/Remove Packages & Sources) – From the manage page you can Add/Remove Sources. Same goes for packages, you can remove or reinstall the packages that you have already installed on your device.

View Memory Status – Here you can see The Memory Status of your device.

Queuing – You can Queue the Package you are installing. To see how this works go here.

Green Highlight is Show the Queued Packages.