What are CTFs?
CTFs are computer security competitions that contain challenges that must be solved in order to recover a “flag” (a specially-formatted string). These challenges often require knowledge in fields such as reverse engineering, cryptanalysis, scripting, and binary exploitation.
How should I get started?
picoCTF is an excellent beginner CTF, as it contains many different types of problems, with more gradually unlocking as you become more proficient in different categories.