> For the complete documentation index, see [llms.txt](https://docs.nexthink.com/platform/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.nexthink.com/platform/references/references-classic/glossary-classic/port-classic.md). # Port (classic) A *port* is a communication resource identified by a transport protocol, TCP or UDP, and a number between 1 and 65 535. Ports are associated to connections. A device connects to a destination through a particular port. {% hint style="info" %} Applies to platforms | Windows | macOS | {% endhint %} \ In reality, two ports are needed to establish a connection: one port in the device and another port in the destination. However, only the port of the destination is important, because it is the one that usually determines the network service. Server applications on destinations listen to connection requests on well-known ports that are associated to standardized network services. For example, the SMTP mail service uses TCP port 25 for incoming requests. For this reason, Nexthink stores information about the destination ports only. The type of the port is determined by the transport protocol. There are two types of ports: * TCP * UDP In addition to TCP and UDP ports, there are two other special types of ports in Nexthink which are associated to connections identified as port scans: * TCP port scan * UDP port scan These special types of ports are not linked to just one but to multiple port numbers. To reflect this particularity, Nexthink assigns to these ports the port number 0. which is actually a reserved port number that is never used. *** RELATED CONCEPTS * [Connection](/platform/references/references-classic/glossary-classic/connection-classic.md) * [Device](/platform/references/references-classic/glossary-classic/device-classic.md) * [Destination](/platform/references/references-classic/glossary-classic/destination-classic.md) * [Object](/platform/references/references-classic/glossary-classic/object-classic.md) RELATED REFERENCE * [Network and port scan conditions](/platform/references/references-classic/database-information-and-organization-classic/network-and-port-scan-conditions-classic.md) --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter: ``` GET https://docs.nexthink.com/platform/references/references-classic/glossary-classic/port-classic.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.