I wouldn't say the lack of a seed is the difference between a CSPRNG and a PRNG. That's more the difference between a CSPRNG and a stream cipher, where the "seed" is called a "key" and "IV".
PRNGs (Pseudo Random Number Generators) are predictable. CSPRNGs (Cryptographically Secure Pseudo Random Number Generators) aren't (if they're working). HWRNGs (Hardware Random Number Generators) that aren't debiased via a CSPRNG or similar produce nonuniform output (not suitable for cryptography or most other uses directly). TRNGs (True Random Number Generators) might not exist in this universe (deterministic interpretations of quantum mechanics are consistent with observation), it's safer to assume they don't and avoid the term entirely.
PRNGs (Pseudo Random Number Generators) are predictable. CSPRNGs (Cryptographically Secure Pseudo Random Number Generators) aren't (if they're working). HWRNGs (Hardware Random Number Generators) that aren't debiased via a CSPRNG or similar produce nonuniform output (not suitable for cryptography or most other uses directly). TRNGs (True Random Number Generators) might not exist in this universe (deterministic interpretations of quantum mechanics are consistent with observation), it's safer to assume they don't and avoid the term entirely.