What makes IPAS stronger than "regular" beers I've only tried IPAS once, but when I can regularly drink 6 beers without feeling any type of alcohol in my system, it only took one and a half pints for me to feel the alcohol kicking in when drinking the IPA. I just know what it stands for but I have 0 knowledge about them, are they beers? how are they much stronger than regular beers?
Answer to the easiest part of the question: Yes, IPAs (India Pale Ales) are beers.

Unfortunately, there isn't a clear and concise answer to the rest of you question. 

Let's assume, for the sake of argument, that by "regular beer", you mean Budweiser. Budweiser sits at 5% ABV. IPAs are often in the 5-7% ABV range, so let's call an "average" IPA 6%. You will feel the alcohol substantially more quickly in the 6% IPA than in the 5% Budweiser.

Lifehacker has a nice article that explains this phenomenon well, but it boils down to the rate at which your body can process alcohol. Suppose that 1% ABV corresponded to 1 "alcohol unit." If, for example, your body could process 4.5 alcohol units/hour, after 6 pints of a 5% ABV beer (1/hr), you'd have 3 alcohol units left in your body [(5.0-4.5)*6]. However, you'd reach the same mark after only 2 beers (1/hr) of a 6% ABV beer [(6-4.5)*2].

TL;DR Version: It probably has to do with the beer's ABV you were drinking.

Side note: There is a lot of variability in strength within any given style. If you like IPAs, you should check out Session IPAs - They are IPAs designed to be lower in ABV than the average IPA, so you can drink more of them in a drinking "session." For a list of the top Session IPAs and more information on the style, check out Ratebeer's Session IPA page.