Using only terms from the question (doubt 5 yos know what source code means)...
Sometimes you can, but only in really simple sites.
Most of the time the code you see when you access the website isn't the real source code. Stuff is often happening that changes the code that you can access. Also when the website talks to other websites, they can tell if it's not talking from where it's supposed to be so they won't talk back.
TheJamhead t1_j6cq64y wrote
Reply to ELi5 : If you can access a website, why cant you steal the source code and make a 1:1 copy of it? by 13lettersinhere
Using only terms from the question (doubt 5 yos know what source code means)...
Sometimes you can, but only in really simple sites.
Most of the time the code you see when you access the website isn't the real source code. Stuff is often happening that changes the code that you can access. Also when the website talks to other websites, they can tell if it's not talking from where it's supposed to be so they won't talk back.