What is the difference between Solution Architecture & Technical Architecture?

As a general rule, the practices of Enterprise architecture, Solution architecture, and technical architecture, are distinguished by their scope.

Enterprise architecture deals with organizational strategy and direction. Enterprise architects design strategic road maps, reference models, and the like. Typically the scope of an enterprise architecture effort is comprised of multiple projects or initiatives and does not get down to specific technological details.

Solution architecture has a slightly more refined focus. Typically solution architects will be tasked with designing how a particular business objective will be achieved or problem will be solved. Solution architects will generally define what specific technologies and process changes/improvements should be used and work at the program/project level. The solution architect provides direction and guidance to the project team and bears responsibility for setting tactical strategy. Solution architects ideally have broad experience in many technical disciplines as well as a solid understanding of business and project/program management principles.

Technical architecture (also sometimes called domain architecture or simply engineering) has the most refined scope and the highest level of technical detail. Technical architects typically operate in one or two disciplines and determine how best to execute specific tasks. Technical architects also typically bear responsibility for designing and managing the systems within their disciplines. For instance, a senior network engineer might also be called a technical architect if their responsibilities also included designing additional capacity and/or operational maintenance policies and procedures.

In addition, the technical architecture role typically has responsibility overlap with systems manager and systems director titles but architects typically do not have direct reports.