system
Given the following post, respond as if you're commenting on Reddit:
human
C-string

What is a c-string in c++? How is that different from just a string?
gpt
There are two common ways of representing strings.  One is to store a length along with the characters, and the other is to say the string goes until you hit a specific character, usually a NUL, which is represented in C as \0, and has the numeric value 0.

At the time the C language was invented, memory was really expensive, and prefixing each string with a length was a waste of memory compared to adding a single character at the end.  If it's 1 byte, you can only have strings up to 255 characters.  If it's 2 bytes, you're wasting 1 byte per string, and you're limited to 65535 characters.  And if it's 4 bytes, you're wasting 3 bytes per string.

So C was given a NUL terminated string as the built in representation.  Pascal was given strings which store the length prefixes.  The two competing standards were commonly referred to as C strings and Pascal strings.

When C++ came around, it was given a std::string class, which stores the length along with the string.  Since C++ was built on top of C, and you can use C style constructs just as easily as C++ classes, when you're talking about strings in C++, it's important to differentiate that a given string is a std::string or an old-style NUL terminated string.