it's a lawn tractor, like this , you can notice the rear wheels are SMALLER than the sterring wheel so that should tell you even more
http://www.curbsideclassic.com/wp-content/uploads/2013/05/CC-196-023-900.jpg

mostly used for lawn mowing as that mower part is detachbale, they are called wrongly long mower tractors as they can do other jobs too with different attachments

modern garden tractors are the same , you can detach that part and use it for other purposes as sen here

same John Deere 210 with mower and without it
http://www.tractordata.com/ltphotos/F000/22/22-td3b.jpg
http://www.pretty-cars.com/data_images/gallery/03/john-deere-210/john-deere-210-01.jpg