NSX-T Edge nodes provide routing services and connectivity to networks that are external to the NSX-T deployment.
NSX-T Edges are required for establishing external connectivity from the NSX-T domain, through a Tier-0 router over BGP or static routing.
Additionally, you must deploy an NSX-T Edge for stateful services at either the Tier-0 or Tier-1 logical routers
NSX-T Edge Cluster represents a collection of NSX-T Edge node appliances that have the same settings and protocols involved in high-availability monitoring. An NSX-T Edge Cluster is required to create a tier-0 or tier-1 gateway with stateful services (e.g., NAT, load balancing, etc.).
An NSX-T Edge cluster should only host edges of identical types and capabilities (VM or bare metal).
An NSX-T Edge cluster does not have a one-to-one relationship with a vSphere cluster; therefore, a vSphere cluster can run multiple NSX-T Edge clusters, or an NSX-T Edge Cluster can span numerous vSphere clusters.
How to deploy an edge

System > configuration > Fabric > Nodes > Edge Transport Nodes > Add Edge Node

Provide name and FQDN and select the form factor size. I always recommend starting with a large.

Enter password credentials

Enter your compute manager, select the cluster you want to deploy (Mgmt. in my example) and select your datastore

Enter your Mgmt. IP and default GW
Select your management interface IE Mgmt. port group
DNS and NTP server

Finally, need to give the edge switch a name
Select your overlay-TZ you created in an earlier blog
Select the uplink profile based on your design
Use IP Pool
Select the IP Pool created in an earlier blog
Select interface and choose the port group assigned for your edge uplinks

Before clicking finish click add switch

Fill out the same information but this time for your VLAN backed network

It takes a while for the deployment to complete. Refresh until up.

To add second edge repeat above steps

Next we want to place both NSX-T edges into an edge cluster

Add edge cluster

Name the cluster and select a profile
Then move the two nodes over
Add
Summary
As you can see a lot of prep needs to go into deploying your edge nodes/cluster. Everything from VLANs, port groups on virtual distributed switch to IP information. Once you have performed all the proper planning then you will find it easy to get your edge stood up.