ENTP strive to change things, improove the world arround them with new ideas. The point is to discover new possibilities in the world... They have good intuition and the sensation/experience is not as important. They prefer to explore and uncover the hidden possibilities and they hate procedures, routine, activities wich are already familiar and don't hide any new possible meaning are boring to them. Their foccus on the objective world is in the things that "hide" possibilities. "Maybe this, maybe that... perhaps this is because of that... What if blablabla". The sensations are subordinated to their intuitive persuits... sometimes they don't notice they need to eat, because they don't foccus on the strongest sensations. They notice only when they are starving. Unless they are thinking about the possibilities that eating on time could bring to their life... but in that case they are eating on time not because they obbey the sensation of hunger... it is still because of the possibility they envision. But in general, everything that is fixed and repetitive is annoying to them. They don't like to waist too much time thinking about the past, reviewing the facts, searching in their memory for the fixed things that happened just for the sake of it. So this makes a little forgetfull or clumsy with "basic" and simple things - For example, they forget to bring their jacket because they don't "waiste" their time recalling the last time they went without a jacket to that place and it was cold. Because whatever new discovery/hidden possibilty is in their mind is more important. But this can sometimes be more serious like making very sudden and blunt life decisions simply because they are too infatuated with some new possibility they are envisioning... Or taking too much risks in a new business.. being somewhat naive because they might think their new idea is briliant but they forget to consider all the repetitive maintenance and precautions they don't like to think about, and because of that they sacrifice stability for things that are simply too risky. That is how not playing it safe can make them irresponsable.
ESTP strive to experience the world arround them. To live the experience itself. The point is having the experience, right here, right now and experience it to the fullest. They are immersed in the here and now and don't like to plan for the future or waiste time thinking about the possible consequences. Their foccus is on the objective world as well but it is on what is happening... more precisely the strongest sensation is the one that captures them. Sensation being: visual, auditorial, taste, scent, touch, etc.
They also need stimulation and are not the biggest fans of routine but what they truly hate is to be hindered from experiencing things to the fullest in the here and now. Everything that is very annalytical, that makes them think about the future, the implications, thinking about the different perspectives that are possibly driving people to do and say certain things, the outcomes that come from people's perspectives, etc... This makes them feel like they are not living their true life because it's not possible to foccus on your sensations while you are trying to read another person's mind, planing your life for the next 5 years or trying to predict what will happen tomorow.
Sometimes this makes them irresponsable also but in the sense that (for example) going beyond the speed limit is a great experience but if they thought about the long term consequences they wouldn't have to pay that ticket, or have an accident. Or sometimes they are so immersed in the good things in life and suddenly they waisted all their money with good food and clothes, but suddenly they are old and they could have invested the money or simply not spending it.
I hope this gave you a good general idea of the key differences. These are the most proeminet struggles in their lifes. The balancing of their good aspects with the negatives that come attached to their way of being.
Please note that these are just examples. The key of their differences are not the behaviours, but the "Why?". The reason and their motivations are the key to their differences