How would anyone be able to tell you what kind it is or what is wrong with it or give you any advice with no information?
If you care about getting some help, you need to: post a couple pictures of your tree, overall view and closer up view of leaves, if any are left. If it has zero leaves, it will be harder to identify. If it really doesn't have enough leaves to get a picture of, then you need to do the best you can to tell us what the leaves were like... more like needles, like juniper
https://c1.staticflickr.com/3/2775/5847 ... 241c_b.jpg
broad leafed like ficus:
notched broad leaves = Fukien tea
https://eschmidtpabonsai.files.wordpres ... c03491.jpg
https://i.istockimg.com/file_thumbview_a ... i-tree.jpg
That's a few of the commoner bonsai types. But even if you can ID it from this, if you want help to figure out what is wrong with it, you need to post the pictures.
Also you said you don't water it daily (good), but how often and how (much/ process) do you water? What else have you done to it? Fertilized? Pruned? Repotted? Trimmed roots? Misted? It is on a table, indoors. How much light does it get (hours of sun a day)? Assuming it is near a window, what direction does the window face? Did the leaves just fall or did they turn brown first? Get spots? What is the soil like that it is in (soft, peat mossy vs gritty, gravelly)? Where are you located and what temperature, etc conditions has it been in? What season are you in (we get people writing in from Australia, etc, where it is fall going in to winter)? Is the tree near a radiator or heat vent?
It may well be dying, but at least we may be able to help you figure out what went wrong. The more information you can give us, the better help we can give. Zero information = zero help.
Welcome to the Forum, anyway ...