Is CryptoLocker a ransomware?

Could you elaborate on whether CryptoLocker falls into the category of ransomware? Given its reputation for encrypting files on victims' computers and demanding a ransom for decryption, it seems to fit the definition. However, I'd like to hear your professional opinion on this matter. Specifically, what characteristics of CryptoLocker align it with the broader classification of ransomware? And how does it differ, if at all, from other types of malware? Your insights would be greatly appreciated.