Many call it the TOEFL Test (even the TOEFL website itself), but since TOEFL abbreviates as "Test of English as a Foreign Language", calling it "TOEFL Test" is sort of redundant. I am writing this since the node by etoile is slightly outdated, and looks a bit like an ad, like this quote for example: "The TOEFL is available to all individuals worldwide regardless of age, gender, race, nationality, or religion" - yes, and you pay tons of money for it. You could put pretty much the same slogan on a carton of cigarettes - that doesn't mean it is a good product for you.
The TOEFL tests your English listening, reading, speaking and writing skill in four separate categories, roughly an hour each, including one break. The four parts are weighed equally (30 points each) for a final score out of 120 points. I personally would estimate that the majority of native speakers would not score above the 110 point range, but that's just an aside. Universities typically require a score of around 80-90 or above, only some require a higher one. Written tests still exist, but the computer-based tests seem more common.
Each round tests about 15-20 people. They verify your ID and make a photo so you will have a hard time letting someone else fill in for you. You get a headset which you use for the listening and speaking parts. The keyboard is a standard English one which is relevant if you are used to other settings. The computer monitors are separated by a partition, so each test taker has a sort of little cubicle that would make it very obvious if you are looking at another person's monitor. There are two or three instructors who look around so you won't cheat. The speaking part is perhaps the weirdest as you will be talking to the computer with absolutely no feedback.
By now, many universities in non-English-speaking countries require an English certificate in certain fields. I told the university that I had written papers in English and done many courses in English, but that was not enough. To prove that my English is sufficient, I needed to pay money for a certificate. There are several big English certificates available. I personally took the TOEFL only because the of timing issues, as for example the test dates for the Cambridge certificate were a bit later and I wanted to get this out of the way as soon as possible.
The TOEFL is the main product its company, the Educational Testing Service (ETS), is offering, but there are a number of other more or less useful services they offer accompanying the test. For example, ETS considers the score report they send you after completing the test an extra service. Lucky as you are, sending one of them to you is included in the price, but if you want more you have to pay extra. Also included in the price of the TOEFL is the service of ETS mailing your score report directly to up to two institutions of your choice. What is useful about this service?
Let's see: The score report might arrive weeks or months before your actual application to the university. Do you believe the uni administration will keep the score reports on hold and file them just in case that at some point in time the test taker will also send in their application? This is a lot of additional bureaucratic weightlifting they are expecting the unis to do, and I personally would not rely on that. And if you do, you'd have the minimal benefit of having one document less to add to your application for university, but the fear that this document will end up missing, which may get you rejected from the uni. In sum, the one service included in the price is useless.
The prices for the test itself, and the other products, are, honestly, pretty ridiculous:
TOEFL Test: $245 (in Germany, may vary by country)
2-week preparation course on test location: $420
Online Preparation test: $45.95
Online "Value Pack": $148 - get a "certified" practice guide, do the online practice test, and pay $35 less for the actual TOEFL test, but get force fed five additional score reports that you are paying for!
Obviously I have not used any of those extra services as I'm not a millionaire, and even then I'd probably rather waste my money on something else. In sum, I personally would not recommend to take the TOEFL over any of the other certificates. On the contrary, they are actually a little cheaper from what I know, so take those if the test times fit your schedule.