This is going to be a bit complicated to explain, so do your best to follow if you can.
When WCW was created after Ted Turner bought Jim Crockett Promotions in 1988, they still used the NWA World Heavyweight Championship with the famous Big Gold Belt representing it as their top title.
Ric Flair would lose the NWA title (still Big Gold Belt) to Sting in 1990. Flair would win it back. This title win is recognized by WWE as the first WCW title reign.
During 1991, Flair would lose the NWA title to Tatsumi Fujinami in Japan. Japan recognized the WCW and NWA titles as separate, while WCW didn't. Crazy huh?
Flair would eventually beat Fujinami in May 1991.
One of the most historic and famous events happened later that year when Flair left WCW for the WWF and brought the Big Gold Belt with him. WCW stripped Flair of the WCW (and effectively the NWA title).
They crowned a new WCW champion when Lex Luger beat Barry Windham in a cage, despite the "We want Flair" chants.
WCW created a new WCW title belt, which Luger held. Eventually a new NWA champion was crowned as well when Masahiro Chono beat Rick Rude for the title in Japan. The title belt to represent the NWA title was now the Big Gold Belt that I assume WCW got back from Flair.
So WCW at the same time had two world champions, 10 years before WWE would.
Chono would lose the NWA title (still Big Gold Belt) to The Great Muta in Japan during another WCW/NJPW event.
The Great Muta would then drop it to Barry Windham in 1993. Now, during this time, Ric Flair had returned to WCW. Flair would then win the NWA title from Windham.
In September of 1993, WCW would leave the NWA. Flair was still the NWA champion holding the Big Gold Belt, but NWA stripped him of that title which led to them having a tournament in 1994 in a company called Eastern Championship Wrestling with Shane Douglas winning the title and the physical belt being the famous '70s and early '80s Dome Globe design. We all know what happened after that.
From that point on, the NWA title was an Indy title, until TNA made it their top title. Currently the NWA title is back to an Indy title.
However, WCW still recognized Flair as a champion. But Flair would lose the Big Gold Belt to Rick Rude, and the title was actually for a time just called The Big Gold Belt.
The title was then renamed the WCW International World Heavyweight Championship going off of a fictitious section of WCW called WCW International.
Rude would ultimately lose that International title to Sting after a couple of other reigns.
Ric Flair in December of 1993 would beat Big Van Vader for the WCW Title at Starrcade.
In June of 1994, Hulk Hogan signed with WCW.
So, WCW decided to have one World Championship to give to Hulk Hogan.
Sting defending the WCW International World Heavyweight Championship, being the Big Gold Belt, faced Ric Flair who was the WCW Champion at Clash of the Champions XXVII, where six years earlier they met at the first Clash in their famous 45-minute draw for the NWA Title.
Ric Flair would win the match, and unify both titles. Then the WCW Championship would be represented by the Big Gold Belt.
Flair would then drop the title to Hulk Hogan in Hogan's first match in WCW. The rest is history.
Hopefully this wasn't too confusing.
(The Big Gold Belt has actually represented four different championships now: the NWA Championship, the WCW Championship, the WCW International Championship and now currently the World Heavyweight Championship in the WWE with the WWE logo stamped on the very top.