Skills are one of the most important parts of a good CV. As a composite, they reflect your sum of experience and the role to which you would be best suited. Most job adverts will have a listing of required or desirable assets, and the ideal CV will intersect with this requested skill set as much as possible.
Caveat employer
However, an individual's skill set is often hard to describe in one short section - and the quantity of experience doesn't indicate quality of experience. A programmer with a purported ten years experience in a given language could potentially be less able than another with just one or two. This can inevitably pose a problem, especially for employers looking for proficient professionals in a particular area.
Those claimed 'ten years of experience' could consist of superficial, occasional usage of the skill in question spanning the last decade, where only the subject surface is scratched and advanced topics are left unlearned. However, just one or two years of more intense, continuous experience within a given field or with a specific language could mean that the applicant is quite proficient.
Decoding stated experience
The above is hypothetical, of course - generally a greater quantity of experience within a field indicates the more skilled candidate. Nonetheless, it is a hazard for both candidates and for interviewers to rely absolutely on the level of skill stated on a CV - particularly using an ambiguous metric such as 'years of experience', or something equally as soft a measurement (non-qualified descriptions such as 'highly proficient', etc).
To really ascertain the level of proficiency in a skill area the candidate should be put to the test - either through an informal Q&A session with a technically-minded person or with a more formal testing procedure.
Presenting your skills
Problems aside, the skills listing on your CV shouldn't be overlooked. In many cases it is the passport through the first stage of selecting the most suitable candidates for interview. Indeed, in the pre-interview phase the CV is the only indicator of aptitude.
If you're applying for a position that mandates a certain skill set, you should think carefully about how best to present the skills you possess with your CV. Should a position state that '3 years of professional experience is required' within a certain field, and you can only claim 1 or 2 but are otherwise of a suitable proficiency, you should ideally emphasise any other contributory experience.
You will need to be careful not to disqualify yourself at an early stage - if you don't meet any posted required standard you may be rejected at the first hurdle. Ideally, the person responsible for reviewing your CV will be aware of some of the issues facing skill metrics.
On the other hand, you must be careful not to overstate your skills - should you reach interview any lack of supposed experience may become apparent. Balance is the key - you need to fit your applicable skills as best you can to the listed requirements, highlighting your skill strengths while mitigating any apparent weakness.
