Lync is an enterprise-ready unified communications platform. With Lync, users can keep track of their contacts availability; send an IM; start or join an audio, video, or web conference; or make a phone call—all through a consistent, familiar interface. Lync is built to fully integrate with Microsoft Office.
Questions with this tag should refer specifically to versions of Microsoft Lync 2013. Anything related in general (non-version specific) to Lync should be tagged with lync

Version Relation:
- Previous: lync-2010
How it works
Organizations can purchase Lync Online as a standalone service from Microsoft Office 365 or as part of an Office 365 for enterprises suite that includes Lync Online, Microsoft Exchange Online, Microsoft SharePoint Online, Microsoft Office Professional Plus, and Microsoft Office Web Apps. Organizations that subscribe to Lync Online retain control over the collaboration services they offer to users, but they do not have the operational burden of on-premises server software. With the Lync Online multi-tenant hosted plans, Lync is hosted on multi-tenant servers that support multiple customers simultaneously. These servers are housed in Microsoft data centers and are accessible to users on a wide range of devices from inside a corporate network or over the Internet.
Features
Basic features include instant messaging, Voice Over IP, and video conferencing inside the client software. Advanced features are related to integration with other Microsoft software:
- Availability of contacts is based on Microsoft Outlook contacts stored in a Microsoft Exchange Server
- Contact lists can be retrieved from a local directory service, like Microsoft Exchange Server
- Microsoft Office can show if other people are working on the same document
- All communication between the clients is done through a Microsoft Lync Server server. This makes communications more secure, as messages do not need to leave the corporate intranet, unlike with the Internet based Windows Live Messenger. The server can be set to relay messages to other instant messaging networks, avoiding installation of extra software at the client side.
- A number of client types are available for Microsoft Lync, including mobile clients.
- Uses SIP as the basis for its client communication protocol
- Offers support for TLS and SRTP to encrypt and secure signaling and media traffic.
- Allows sharing files.
The main new features of this version are the addition of real-time multi-client collaborative software capabilities, (which allow teams of people to see and simultaneously work on the same documents and communications session). These features are implemented as follows:
- Collaboration through Whiteboard documents, where the participants have great freedom to share text, drawing and graphical annotations.
- Collaboration through Power Point documents, where the participants can control and see presentations, as well as allow everybody to add text, drawing and graphical annotations.
- Polling lists, where Presenters can organize polls and all participants can vote and see results.
- Desktop sharing, usually by allowing participants to see and collaborate on your windows screen.
- Windows applications sharing, by allowing participants to see and collaborate on a specific application.
All collaboration sessions get automatically defined as conferences, where clients can invite more contacts. Conference initiators (usually called organizers) can either promote participants to act as presenters or demote them to act as attendees. They can also define some basic policies about what presenters and attendees are able to see and do. Deeper details of policy permissions are defined at server level.