The electrical infrastructure needs the integration of communication technologies, and in recent decades the progress has been significant. Therefore, this work presents the latest advances in this subject, as well as new functionalities.The work brings together the advances in automation, from the early stages to the present day. At the moment, the Smart Grid needs to use communication technologies to enable a response to demand, which will allow a different relationship between customer and company. The work presents the existing network architectures and communication protocols used in the Smart Grid. The document presents the challenges of electrical infrastructure, and shows the benefits and drawbacks of different communication technologies. In summary, the paper shows the parallel evolution of the communication technologies and the electrical grid, as a basic aspect for the development of new functionalities and services for all the agents involved in the power generation-transmission-distribution system.