What is Best seo or sem..?

You don't have to choose between the both of them. They are both extremely important to a web presence. SEO should be done first becuase it takes aspects of that website and makes it more efficient to navigate and index. Sem comes later and it consists of strategies that are used which are meant to promote awareness and get relevant traffic on your website.

I prefer SEO in all aspects. Because SEO helps in many ways like- sales, brand promotion, keyword ranking, reputation, visitors and more.

SEO and SEM are both best because of its specialties in different related field.

SEO & SEM together provides better result, as through SEM you can better result instantly and fast, where as SEO is a slow process. So better to go for both together.

If you have Money do SEM other wise do SEO it depends on you money background.

SEM, or Search Engine Marketing, is a wider activity than just SEO. Search Engine Marketing actually can include SEO, but more commonly has Paid Ads as its primary focus.