The Story Behind Jurassic Park
When John Hammond (Richard Attenborough) finally figures out how to bring dinosaurs to life, he is over the moon and creates a park, Jurassic Park, where he can share his creations with the world. But just as soon as he's about to open it to the public, one of his employees gets attacked and killed by a velociraptor. John cannot help but doubt the security of the park, and he seeks the opinions of three specialists: Dr Alan Grant (Sam Neil), who is a palaeontologist. Dr Ellie Sattler (Laura Dern), who is a paleobotanist; Dr. Ian Malcolm (Jeff Goldblum), who is a mathematician and, of course, a lawyer. Donald Gennaro (Martin Ferrero). At the same time, he brings in his grandkids, Lex (Ariana Richards) and Tim (Joseph Mazzello), as he wants them to see the majestic creatures long before the world has a chance.
The Characters of Jurassic Park - Experts, Lawyers, and Grandkids

The doctors, lawyers, and grandkids arrive and get a grand tour of the park, where they see the dinosaurs going about their lives. They remain in awe as they learn about how John and his team used genetic engineering to bring them to life. Even so, some things do not go as planned. For one, the dinosaurs do not appear in the expected sequence. Secondly, a triceratops takes ill during the tour, such that Dr. Sattler has to leave to tend to the issue. Dr Malcolm also adds that nature is unpredictable, which acts as a prelude to what's about to happen. After all, as the group embarks on the tour, a park programmer, Dennis Nedry (Wayne Knight), is busy deactivating the security so that he can steal the dinosaur embryos.
The Park Tour Turns Dangerous - Chaos Unleashed
Hell breaks loose when the tour vehicles stop outside the Tyrannosaurus Rex's (T. Rex) paddock. With the systems down, the dinosaur makes it past the gate and launches an attack. Donald runs away, leaving the vehicle and seeking solace in a bathroom. But the T. Rex catches up with him and eats him. Realizing how dire the situation is, Dr. Alan takes John's grandkids and leads them into the jungle.
Tragic Events and Escaping the Island - Survival at Its Peak

As all this is happening, a storm approaches and worsens the situation. Given the sudden turn of events, things turn so chaotic that even Dennis gets trapped in his mess. As he tries to take the embryos, he comes across a Dilophosaurus, which spits venom on him before killing him.
John and Dr. Sattler are back in the station, trying to restore the power at this time. It soon dawns on them that the Velociraptors are running wild. As the team tries to regain control, it suffers one loss after another.
The park engineer gets killed while working on the system, the warden gets killed as he tries to hunt the dinosaurs, and Dr. Sattler almost becomes another statistic as she works on the power. Luckily, the velociraptor misses her. John's grandkids and Dr Grant finally make it back to the visitor center with the velociraptors closing in on them. Lex, a computer whiz, manages to get the security systems back online. With the dinosaurs at bay, John, his grandkids, Malcolm, Dr. Grant, and Dr. Sattler leave the island, lucky to be alive.
Effects in Action
Making an audience believe that the cast is in danger is quite the task. But with the use of animatronics and computer-generated images (CGI), the directors and producers of this film hit the nail on the head. They used large-scale mechanical models that enabled them to depict the weight and physicality of the animals for the screen. And with CGI backing them, they were able to engineer digital effects that made the motions realistic.
The Iconic T. Rex Scene - An Unforgettable Moment of Suspense

A good example would be when the tour vehicles stopped in front of the T. Rex paddock. The storm was approaching, and the rain was coming down hard. Unbeknownst to the guests, the security system was down. So, when the T. Rex came crashing through the fence and attacked them, the suspense in the air was palpable as it all seemed very real and scary. The same effects were evident when John's grandkids were hiding in the kitchen while being hunted down by the velociraptors. The effects covered the stealthy dinosaur movements around the room, with the shots capturing their every sound.
And let's not forget the scene where the kids and Dr. Grant run through a field as they try to beat the speed of Gallimimus. The whole setting is so vivid that it almost feels like a recreation of something that actually happened. It's no wonder that this film has so many sequels!