Many fans of the US version of Big Brother consider the second season the first real season of the show. That is because the format of the first season is entirely different than the seasons that followed.

Related: Big Brother: The 10 Most Nominated Houseguests Ever

The first version of the reality show began in the Netherlands and there have been many iterations in various countries. When Big Brother first aired in the US, many viewers found it to be boring and dull. This resulted in the creation of a new type of game, one that kept the same basic concepts but provided twists and turns that would keep any viewer interested.

Changed: The House

HOH Room Big Brother

The Big Brother house wasn't always the lavish house modern viewers are used to seeing. As the years have gone on and the budget and popularity have increased, the house has continued to get more sophisticated and spacious.

The first season featured a basic one-story house with two bedrooms, a kitchen, a dining room, and one bathroom. This vastly differs from the current two-story house with a large yard, HOH suite, and more.

 The Same: Constant Surveillance

Big Brother 17 Live Feeds

At its core, Big Brother is a social experiment in which individuals from different walks of life live together while being constantly monitored.

One thing that makes the show so unique is access to the live feeds, in which viewers can watch the houseguests' every move. This constant surveillance is what gives the show its name and has been a crucial element since the beginning.

Changed: America's Vote

Da'Vonne Wins AFP

Each season of Big Brother has offered viewers a chance to impact the game by voting from their homes. However, the significance of these votes has changed greatly since the game's inception. During season 1, America actually voted on which houseguest to eliminate each week. They also voted on who would win the game in the end.

RELATED: Big Brother 22: 5 Traditions That Need To Go Away (& 5 That Can Stick Around)

Now, America's vote is mostly used to impact the game by assigning powers or protections to houseguests, providing alternative food options to players on slop, and voting for America's Favorite Houseguest. Many fans think that America's vote has too much influence on the game as some twists have greatly impacted the trajectory, but it is interesting to consider how little power America has when comparing the first season to today's game.

The Same: Isolation From The Outside World

Janelle and Kaysar Reunite big brother

Houseguests often form fast bonds with other players in the house, forming meaningful connections that can last a lifetime. This is partially because the houseguests are completely isolated from the outside world.

Without access to friends, family, phones, or the internet, the houseguests are forced to get to know each other. Thrusting the players into a bubble in which they can only interact with each other has always been and always will be a crucial part of the show's format.

Changed: Head of Household

Cody Nominates Nicole and Donny for eviction

The Head of Household is the most powerful player in the game. Alone, this houseguest decides who to nominate for eviction and experiences luxuries such as their very own HOH suite. This power is such a crucial part of the current format that some may struggle to remember a time where there was no HOH.

However, this role was absent from the first season of Big Brother. Instead, the houseguests would collectively vote on who to nominate for "banishment" and the top two vote-getters would be at risk of leaving the game.

The Same: Eliminations

Kat Dunn eviction interview with Julie Chen

Though the amount of houseguests has increased and eliminations are now called "evictions" rather than "banishments," the basic concept is the same.

A larger number of houseguests enter the house and one at a time, they are sent out the door until only the final 3 remain. These final 3 then battle it out on finale night before a winner is crowned.

Changed: Power of Veto

Rachel Wins the veto

The power of veto has seen many changes and developments throughout the history of Big Brother. There have been golden powers of veto, diamond powers of veto, and silver powers of veto.

But, in the first season of Big Brother, there was no power of veto at all! This is another example of the major format changes the game has undergone as the POV is such an important part of the current game.

The Same: Julie Chen

Julie Chen on Big Brother

While many viewers have watched at home as the game has continued to change, one person has experienced all of the changes first hand. Julie Chen has been the host of the popular show since the first season.

RELATED: Big Brother: Top 15 Seasons, Ranked

Though she had a co-host in season one, it's still remarkable that she has managed to consistently host each season since the show first aired in 2000. Julie has cemented herself as a staple in Big Brother history.

Changed: The Houseguests

The cast of Big Brother 20 in the pool

Many fans of the show have criticized the direction in which the casting process has gone. During the first season of the game, many of the houseguests seemed like average people from different walks of life. There was much more diversity in the ages and careers of the players.

Now, the houseguests seem more formulaic. The show seems to cast specific archetypes - the jock, the nerd, the quirky girl, the token minority - and the houseguests are usually in their 20s and stereotypically attractive. There is some hope that this will change with the upcoming season as Big Brother has pledged to have 50 percent of their cast be BIPOC after pressure from fans to have a more diverse group of houseguests.

The Same: The Prize

Paul and Josh Final 2 Big Brother

Everyone hopes to come away from Big Brother with the half-million-dollar prize. But it's crazy to consider that this prize money has actually remained the same since season 1.

$500,000 went a lot further when the show first began 21 years ago and this has many fans saying that it is time for them to increase the jackpot.

NEXT: Big Brother: 10 Most Memorable Quotes