Besides there being regional differences between CVs and resumes, the underlying professional reasons for writing either remain almost the same. The general purpose may stay the same, but recruiters are getting keener in what they are looking for. Recruiters that are asking for a CV may want to get specific information that those asking for a resume may not find it necessary.
So what are the main differences?
The purpose of writing a CV is very different from writing a resume. A CV will include more details about you. This includes information that may not be relevant to any work area. A recruiter that asks for this may not be specifically looking for a specific filling, but an individual that can wear more than one hat in an organization. CVs will carry more information even though the grounding may be different. An individual that has achievements in accounting may also have others in sales and marketing or even motivational speaking. These may not be needed at any point for a single job, but will, either way, have cause and effect when it comes to some jobs. A resume will have much more focused information. Recruiters that ask for a resume are looking for information that is relevant to the position you are applying. This also makes it much more consolidated. It also means that you will need to work without many of your achievements. A CV comes in handy when changing your line of career to something different. It also works when starting off in an entirely new environment. A resume will be ideal if you are sticking to the lane and looking for greener pastures along the same carrier.
This then makes the CV much longer compared to the resume. Making it longer should not equate to filling it with fluff and jargon. It still has to be precise and sensible to read. A CV will contain detailed information while a resume will include the information itself. A CV allows you to get deeper into the achievements you have made besides just having a longer list. The achievements will consist of duties, responsibilities, and results. A resume may only allow you to mention the achievement and results for faster perusal. A recruiter asking for a CV may want to read more calling for very clear details. One asking for a resume will not be interested in much except what which is relevant to the company in question. The formation then needs to be straight to the point as well as less personalized in expression. A resume will be about a page long while a CV will take two to three pages.
The fact that the resume is shorter seeking specific information means that the layout will be different. A resume comes with an objective right at the top, may have some photo or impressive design and nonstandard font. The purpose of a resume is to captivate the reader in less than 8 seconds, enabling them to make a quick decision. It should have the achievements and experience of the main body, and that is it.