Most libraries provide computers you can use to access the Internet. If chemicals are being stolen from a lab, you might ask who has access to the lab. Access is approaching or making use of something, or the ability to do so
Sometimes the word is applied to a person. If you work in the same room as your boss, you might have easy access to her. A really good boss will work hard to make herself accessible to her employees. Access is from Middle English, from Middle French acces "arrival," from Latin accessus "an approach," from accedere "to approach."