Technically, "internet" is not always capitalized. It's generally considered a common noun, like "television" or "radio." So, if you're referring to the global network itself, lowercase is fine:
* "I spend too much time on the internet."
However, "Internet" is often capitalized when referring to the specific network, like "the Internet" or "the World Wide Web." This is similar to how we capitalize "Earth" when referring to our planet, but lowercase "earth" when talking about soil.
* "The Internet has revolutionized communication."
Ultimately, there's no strict rule. Both spellings are widely used and understood. It's more about your personal preference and the context of your writing.