What aspect does keylogger software mainly focus on?

Keylogger software primarily focuses on recording keystrokes for information gathering. This type of software is designed to monitor and log every keystroke made by a user on their keyboard, which can be used to gather sensitive information such as usernames, passwords, and other personal data. This function makes keyloggers an effective tool for hackers who want to steal information without the user's knowledge.

While securing personal information, filtering communications, and analyzing software efficiency are all important aspects of cybersecurity and software performance, they do not pertain to the fundamental purpose of keylogger software. Keyloggers are specifically designed to capture and store input data, which is why option B is the correct focus of keylogger functionality.