What features makes D3100 an entry level camera?

Why Nikon D3100 is considered entry level camera?

I've compared the features of D3100 with other mid level camera's like Nikon D90 and Canon 550D. I hardly see difference.

Wanted to know the major difference which makes D3100 as an entry level camera.

Program modes.

1) It costs less than $1, 000
2) It has more "P&S" features than more advanced dSLR's
3) The 550D is an entry level camera

The Nikon D90 Canon equivalent is the 50D.

The new D7000 is in competition with the Canon 60D

That extra wheel on the D90 says it all. Entry-level dSLRs have more controls buried in the menu. Higher-end models have them under your fingertips. Then most higher-end models have more extreme control settings compared to lower-end models of more or less the same year.

Plastic body rather than magnesium alloy weather sealed body
Scene modes rather than the more pro PSAM modes
No Nikon wireless CLS control for off camera flashes
No wireless remote option
No PC sync socket for flash
Less AF points

Adding to the above answers, the D3100 doesn't have a built in auto focus motor. D90 also has a better faster auto focus in some instances. Usually Canon and Nikon cripples their entry level cameras in some way so if one needs a feature they have to buy a better ($$) body, e.g. Spot metering, bracketing exposures, focus points etc.

I think you should go with Nikon D3100 14.2MP Digital SLR Camera
* 14.2-megapixel DX-format CMOS image sensor;
* 3-inch monitor with One-Touch Live View shooting and movie capture
* Full 1080p HD Cinematic Video with full-time autofocus and sound
* Easy-To-Use Nikon Guide Mode with intuitive controls and on-board assistance
http://www.amazon.com/...003ZYF3LO/