The Canon EF-S 18-55mm f/3.5-5.6 Lens is a really cheap lens if purchased as part of a Canon DSLR kit.
But the price is not the only cheap thing about this lens.
The lens mount is plastic. In fact everything on the outside is plastic except for the glass on the 18-55. There are advantages to this construction - light weight (the 18-55 is extremely light) - and of course cost.
There is no distance window on the 18-55. The tiny manual focusing ring is barely usable and is located on the end of the extending objective end of the lens. There is no USM focusing motor (on the kit model) which means there is no FTM (Full Time Manual) focusing.
Even without USM, focusing is not slow or loud. It is not going to break any records, but it seems fine for its intended market.
The 18-55 exhibits barrel distortion on the wide end of the focal length range. The distortion dissapears at around 28mm.
The 18-55 has noticeable light fall-off with a wide open aperture - especially on the wide end of the focal length range. I would expect more vignetting from an EF-S mount lens than an EF mount lens mounted on the same 1.6x FOVCF body, and there is. However, the 18-55 performs better than the Canon EF-S 17-85mm Lens at the lower focal lengths in this regard.
The Canon EF-S 18-55mm f/3.5-5.6 Lens has reasonable center sharpness, especially when stopped down. Corners are very soft on the wide end of the focal length range. Even with the lens stopped down, corners are still soft. This lens performed especially well at short distance on the ISO 12233 chart.
With narrow wide apertures and no IS (image stabilization), the 18-55 is a slow lens for stopping motion (subject or camera). Expect to need good light or a bright flash for this purpose. It also does not easily create a blurred background.
The 18-55 exhibits CA (Chromatic Aberration).
Pictured above from left to right are the Canon EF-S 18-55mm f/3.5-5.6 Lens, Canon EF-S 60mm f/2.8 USM Lens, Canon EF-S 10-22mm f/3.5-4.5 USM Lens, Canon EF-S 17-85mm f/4-5.6 IS USM Lens and Canon EF-S 17-55mm f/2.8 IS USM Lens. The same lenses are pictured fully extended below.
Useable only on a Canon EF-S-compatible DSLR, the 18-55 equates to a 28.8-88mm field of view on these 1.6x field of view crop factor DSLRS. This covers the focal lengths Canon targets for their general purpose lenses.
For the additional price of a DSLR kit over the DSLR body alone, the 18-55 is not a bad value. But you might be surprised by what your DSLR can do with some of the better lenses!
Please note: As far as I know, the 18-55 is only available as part of a Canon EOS camera body kit - or used. The buy button will point you to the USM version which should have a better focusing motor.
Another note: There is now a 18-55 "II" shipping in some Canon EOS body kits. My understanding is that only cosmetic changes were made for the "II" designation. According to Canon, "The major changes are the shape of the zoom ring rubber grip and the tapered area at the front of the lens." The two Canon lenses share the same MTF charts.