If you have a specialization, that means you focus on a specific aspect of a larger topic. If you’re a nurse, your specialization might be pediatric care, which means you focus on providing care to infants and children.
You probably notice that the word special makes up a big part of specialization, which can help you remember its meaning. Your specialization is your special subject or skill. If you’re planning on studying biology in college, your advisor eventually will ask what your area of specialization will be. When you graduate, you’ll know a lot about biology in general, but there’ll be a particular area — such as marine biology or rodent reproduction — that you studied deeply.