# Terminology

## Cloud Interconnect terminology

* **CIC**: Abbreviated name for Yandex Cloud Interconnect.
* **PoPs**: [Points of presence](pops.md), i.e., commercial communication hubs hosting third-party network equipment, including the Yandex Cloud equipment.
* **Cross-connect (XC)**: Two optical fibers at the point of presence connecting the physical port of the customer or telecom provider equipment to the physical port of the Yandex Cloud equipment.
* [Transceiver](transceivers.md): Optical module installed on the customer and Yandex Cloud equipment ports. It provides termination for the optical fibers of the cross-connect.
* **Telecom provider**: Telecommunication service provider that has its own equipment at a point of presence. Typically, you need a cross-connect to connect to the Yandex Cloud equipment via a telecom provider.
* [Trunk](trunk.md): Physical connection at a point of presence between the Yandex Cloud equipment and the customer or telecom provider equipment.
* [Private connection](priv-con.md) (PRC): Connection between the customer site (on-prem) and a [routing instance](../../cloud-router/concepts/routing-instance.md).
* [Public connection](pub-con.md): Logical connection between the customer site (on-prem) and Yandex Cloud [services](pub-con.md#svc-list) without using `VPC`.
* [Support](https://center.yandex.cloud/support): Yandex Cloud technical support team that handles customer requests.

## Cloud Router terminology

* **Hybrid Cloud** is a type of IT infrastructure that brings together the company’s internal IT resources on the one hand and public clouds resources on the other.

* **On-prem**: Customer site hosting their IT resources and network equipment for connection to Yandex Cloud via [Cloud Interconnect](index.md).

* [Cloud network (VPC, Network)](../../vpc/concepts/network.md): Virtual Private Cloud resource. A cloud network is used to provide network connectivity in all [availability zones](../../overview/concepts/geo-scope.md) of a single region.

* [Subnet](../../vpc/concepts/network.md#subnet): Virtual Private Cloud resource. It belongs to a cloud network. Each subnet has an IP prefix (CIDR). Each subnet is always linked to a single [availability zone](../../overview/concepts/geo-scope.md). Cloud resources are connected to a subnet.

* [Routing instance (RI)](../../cloud-router/concepts/routing-instance.md) is a resource you can use to create a specific network topology which may include:
  * IP prefixes of [subnets](../../vpc/concepts/network.md#subnet) belonging to one or more [networks](../../vpc/concepts/network.md).
  * [Private connections](priv-con.md). The number of private connections depends on the network topology type.

* `Routing` is the ability to direct network traffic using the [Cloud Router](../../cloud-router/concepts/index.md) and [Cloud Interconnect](index.md) resources.

* **VPC Stitching** is one of the `Cloud Router` mechanisms providing network connectivity between [cloud networks (VPCs)](../../vpc/concepts/network.md) that are located in folders of the same or different clouds within a single [cloud organization](../../organization/concepts/organization.md).

* **Stitching announcements** are aggregating routes implementing the `VPC-Stitching` mechanism. They are used to create individual types of network topologies to configure [private connections](priv-con.md). Regional in scope, they combine IP prefixes of subnets across all availability zones. Stitching announcements are calculated and added to the [private connection](priv-con.md) configuration by the client. Stitching announcements are not automatically calculated or added to the private connection configuration on the Yandex Cloud side. You will find them displayed in the `ipv4_static_routes` field of the Cloud Interconnect API for [private connections](priv-con.md).