A more complicated answer would be that Las Vegas is home to Downtown Las Vegas and a tiny piece of the Las Vegas strip, (Las Vegas Blvd.) that most people associate with a Las Vegas vacation. Most of the iconic hotels and tourist attractions found on Las Vegas Blvd, also known as the Las Vegas strip, are actually in an area of town that is unincorporated and named Paradise.
Las Vegas Strip Basics
Don't worry about the name: the Las Vegas strip is essentially the strip of Las Vegas Blvd. that runs from the Mandalay Bay Hotel on the south all the way to the Stratosphere Hotel on the North. That encompasses all the hotels that you would typically be familiar with except for those in Downtown Las Vegas and those would be on Fremont Street.
All hotels mentioned here will either be on Las Vegas Blvd or on Fremont Street. There are some exceptions such as The Rio, The Palms, Trump Hotel and the Las Vegas Hotel and Casino(Westgate). However, they are essentially walking distance to the Las Vegas strip, so they are included as strip hotels.
Now that you are completely confused about the Las Vegas strip, just remember that if you get into a taxi and ask to be taken to the Las Vegas strip the cab driver will ask you to be more specific since the total distance on Las Vegas Blvd is about 4 miles from North to South.
The center of the Las Vegas strip is around Flamingo Rd. where the intersection includes Caesars Palace, Bellagio Hotel, Bally's and the Flamingo Hotel. From this intersection, you can walk to the Eiffel Tower, to the Gondolas at the Venetian and to an erupting Volcano. You can also see a giant Pyramid, the Stratosphere Tower and a lake with dancing fountains.