I've encountered quite a few architects with varying titles over the years, and I definitely have my own view on the role of each of them, however it does tend to vary from company to company, and even more so from country to country.
Enterprise Architect - responsible for strategic thinking, roadmaps, principles, and governance of the entire enterprise. Usually has a close relationship with the business, vendors, and senior IT management.
Solutions or Systems Architect - responsible for desiging a high level solution to a specific set of business requirements, within the framework laid down by the enterprise architecture team. This solution may span multiple applications.
Integration or SOA Architect - responsible for the integration and/or business service strategy and governance. Since this role usually spans the entire enterprise it is often performed by an EA, however an integration architect will usually work at a more detailed and technical level than an EA. In a SOA, an integration architect may also be a member (or even leader) of the centre of excellence (or integration competency centre)
Information Architect - responsible for defining data models, master data management / ownership solutions, and data quality processes to support transactional, reference data, and reporting systems throughout the enterprise. Often performed by an EA.
Application Architect - responsible for implementation of, and processes within, a specific application or suite of applications. The application in question may be bespoke of a customised of-the-shelf product. Should have deep knowledge of the product/application and will often be consulted by other architects as part of a larger solution
Those are the most common titles in my experience, but there are other architecture roles that you'll see from time-to-time:
- Technical Architect (for me this is the same as an application architect but others may disagree
- Business Architect (defines business strategy and processes)
- Infrastructure Architect (servers, platform decisions, and often security)
- Network Architect (obvious)