You have googled/searched WF first before posting this.

Anyway, check this link out for guidance: Advantages and Disadvantages of Search Engine Marketing | Internet Marketing News - Search Engine Marketing

SEM = SEO + PPC

Advantages of SEM...
- You get both paid and organic traffic
- You drive more leads for your business
- With good online presence you build a good reputation among your clients
- You get a good exposure among wider range of audience

SEM means Search Engine Marketing. It includes both SEO and PPC. In PPC, you can either function as an advertiser or a publisher.

In either way, you are a part of the same system. As an advertiser, you are paying a search engine money for clicks to your website/offer and as a publisher, you are earning a portion of the money that the advertiser spends on their campaign(s) (the search engine gets a cut - and that's how they make their money).

If using PPC, you will get traffic in no time.

SEM means "search engine marketing" it is very useful for getting traffic from and visibility on search engines.

using SEO will help you in long run but it takes time before you start getting traffic. if you want instant traffic then start PPC and continue SEO in the side run. so that you are getting traffic from search engines instantly and after some time you will have some organic traffic too. so SEO + PPC = SEM.