A 765-kilovolt (kV) transmission line is a type of extra-high-voltage power line designed to carry large amounts of electricity across long distances between major substations across an electric grid.

They are much larger than typical neighborhood distribution lines, and require very wide and very tall structures and wide rights-of-way.

The Texas PUC is that state agency responsible for regulating electric utilities and approving major transmission projects.  The PUC staff are professional employees of the PUC who assist with reviewing utility applications and regulatory cases. Staff may analyze technical information, review filings, ask questions of the parties involved, and provide recommendations during the review process . The PUC Commissioners (currently there are 5) are appointed by the Governor, and make the final decision on whether a transmission project and route will be approved.

PUC Interchange
The Public Utility Commission's online filing and document system. This is where all official documents in a case are filed and made public, including applications, testimony, letters, comments, and rulings. Anyone can search Interchange by Docket Number (or Control Number) to read everything that's been filed in a case, including documents filed by other landowners, the utility, and PUC staff.
PUC Interchange (link)

Interchange Filer
The specific tool within PUC Interchange that the public uses to submit documents into a case, for example, a public comment, a motion to intervene, or a letter of protest. If you want to formally add something to the case record, this is where you upload it.
Interchange Filer (link)

ERCOT is the organization responsible for managing the flow of electricity across most of the Texas power grid.

ERCOT oversees grid reliability, coordinates electricity markets, and conducts long-term planning studies to identify where new transmission infrastructure may be needed to meet growing electricity demand.

A CCN is the formal approval required from the PUC before a major electric transmission line can be built. The CCN process determines whether the project is needed, and which route will be approved.

A TSP is a utility company responsible for building, operating, and maintaining high-voltage transmission lines and substations on the electric grid.

In Texas, examples of TSPs include Oncor Electric, LCRA Transmission Services, and AEP (American Electric Power).

A transmission easement is a legal right that allows a utility company to place and maintain transmission lines on private property. The landowner continues to own the land, but certain uses of the property may be restricted within the easement area.

Utilities often divide large study areas in segments when evaluating possible transmission routes. These segments (such as G4, G5, G6, etc.) are planning sections used to study and compare different routes.

An intervenor is a person, landowner, organization, or government entity that formally participates in a PUC case. Intervenors may submit evidence, ask questions of witnesses, and present arguments during the regulatory review process.

SOAH is an independent Texas state agency that provides administrative judges for many types of regulatory cases, including some PUC proceedings. 

An ALJ is an independent judge who manages the formal hearing process in many PUC cases. The ALJ oversees procedural matters, hears testimony from witnesses, reviews evidence submitted by the parties, and develops a written recommendation based on the record of the case. The ALJ does NOT make the final decision on whether a transmission line or route is approved. The final decision is made by the PUC Commissioners.

The transmission line route that the applicant (the utility) has designated in its application as the route it believes best satisfies the routing criteria required by the Public Utility Commission, including factors like cost, engineering feasibility, and impacts to landowners, habitat, and communities. This is the utility's own proposed route, not a route chosen or approved by the PUC.

Important: The Applicant's Best Meets Route is not a final decision. The PUC (through the SOAH hearing process) has full authority to approve the applicant's proposed route, select an alternative route studied in the application, or approve a modified route combining segments from multiple options. Landowner and public input, intervenor testimony, and the administrative law judge's recommendation can all shift the outcome away from the applicant's preferred route.