Dear guys,

Kindly let me know details about what are the difference between internet marketing, seo, sem, smo.. I have so confused...

Never heard of SMO (and don't have time to google it as I am sure it won't affect what I do in any way shape or form ) but for the others:

SEO:
Search Engine Optimization - Everything you do on your site to ensure that it outranks your competition on the search engine pages. This includes the "Natural/Organic" where via keywords, coding practices, content, etc, and the paid where you actually pay google (and others) for your keywords, bidding for them with other competitors, to ensure a certain position on their search listings page.

Paid listings (Pay-Per-Click, or PPC) appear at the top (yellowish background) and the 8 listings in the right column of the search listings page. The paid listings are typically ecommerce-type sites. You bid for a keyword and the highest bidder gets to see their site at the top. Your ads are typically displayed evenly across the day. You set a budget and if that budget is exceeded (as in say, your particular keyword is $5 and your daily budget is $10 = 2 clicks for that keyword), your ad disappears. This is how the likes of google make their billions, by the way - awoof money.

The "natural/organic" show up in the (larger) left column and can take weeks/months to get your site moving up to the top. Also, since there are others out there, if you don't keep, say, updating your site, your ranking will drop. The keyword for this type is "relevance" - the more relevant your site is, the higher it ranks. Relevant site rankings are more often than not influenced by what your site is. Typically, this refers to research-type sites (like wiki), which explains why such sites come up first, as opposed to ecommerce site. Also, a site that is very specific (say, about white balls) will be considered more relevant than a site that talks about a myriad of things (white, yellow and black balls).

SEM:
Stands for Search Engine Markteting and refers to the "complete package" of SEO and PPC that you do to ensure the success of your site.

Make sense? I have tried to cut out as much "fat" as possible and give it in layman's terms.

By the way, others should feel free to jump in here

Internet Marketing - Is marketing efforts done solely over the Internet. This type of marketing uses various online advertisements to drive traffic to an advertiser's website.

SEO - Is optimizing the page to be easily found and indexable by search engines. This is everything from content writing to getting backlinks.

SEM - Is bidding on keywords through tools like Google AdWords. This can be extremely expensive and time consuming, and should probably only be a short term solution until your site is performing well organically.

SMO - Is setting up and participating in various Social Media sites, like Facebook, Digg, Delicious, etc. The purpose here is to build commuinities of fans and spread the word on your updated content.