While you may think these terms are interchangeable, they are different. Both types of CTOs oversee the use of technology in a firm.However, fractional CTOs typically only oversee a fraction; typically focusing on a specific area. On the other hand, part time CTOsoversee everything while only working on a part time basis.
Part Time CTO
Managing Dev & QA Team
Turning "Business Requirements" into technical requirements and design
Cost Analysis & Budgeting
Dev Hiring and Recruiting
Leading Technical Vision
Fractional CTO
Managing Dev & QA Team
Dev Hiring and Recruiting
Leading Technical Recruiting
or
Turning "Business Requirements" into technical requirements and design
Cost Analysis & Budgeting
Part Time CTO
Managing Dev & QA Team
Turning "Business Requirements" into technical requirements and design
Cost Analysis & Budgeting
Dev Hiring and Recruiting
Leading Technical Vision
Fractional CTO
Managing Dev & QA Team
Dev Hiring and Recruiting
Leading Technical Recruiting
or
Turning "Business Requirements" into technical requirements and design
Cost Analysis & Budgeting
As you can see, a fractional CTO may fulfill the same duties as a part time CTO. However, they tend to only be responsible for a fraction of the duties; allowing a more specific focus.