When we learn a language, there are four skills that we need for complete communication. When we learn our native language, we usually learn to listen first, then to speak, then to read, and finally to write. These are called the four "language skills":
Skill #1: Listening
Skill #2: Speaking
Skill #3: Reading
Skill #4: Writing
Note that these four language skills are sometimes called the "macro-skills". This is in contrast to the "micro-skills", which are things like grammar, vocabulary and pronunciation.