In second language teaching and learning, computer technology extends the types of interactive activities that learners can work on in and outside of the classroom, and therefore it has affected the way that many teachers teach and learners learn. Teachers might, for example, ask students to seek specific information on the Internet in preparation for an information gap activity in class; teachers might indicate awkward expressions in a student's essay and show the student how to find examples of target language collocations in a corpus; and teachers might organize a virtual collaboration between their students and proficient speakers of the target language in another country. These activities and many more add significantly to the repertoire of activities that learners can engage in because of three affordances offered by technology: human-computer interaction, distance written and oral communication, and access to a community with data and creative opportunities on the Internet.