What does an SEM do?

SEM Stands for Search Engine Marketing, it is one of the best practice of Digital Marketing. It is a paid marketing strategy to increase the search visibility. In the past, search engine marketing was a term used to describe both organic search engine optimization (SEO) and paid search. But now, it almost always refers only to paid search marketing. They target select keywords so that when a user searches for those terms, they see an ad from the brand. The brand is charged only if a user clicks on the ad.
Paid search ads can be found on almost any search results page. Here brands pay for advertisement to appear as search result on search engine result pages. These paid placements are typically located at the top and bottom of the page. They include an “Ad” designation to let users know that it is a paid placement. 
What are SEM Platforms?
An SEM platform is a search engine where a brand can place search ads that are displayed when users perform a search. The most common SEM platforms are Google and Bing.

• Google Ads : It is the most widely used SEM platform. Billions of Google searches are performed a day, so it can help you get in front of the largest online audience.
• Bing Ads: Bing claims to connect with 3 million searchers that Google can’t reach. By serving ads on partner sites such as Yahoo and MSN, Bing Ads help you connect with searchers who aren’t exclusively using Google for search.

Some Best Practices of Search Engine Marketing?
Creating effective SEM campaigns requires research and strategy before you set up your campaign, as well as after your campaign is already running. The following tactics can help you optimize your campaigns so that you reach more people, maximize your budget, and drive more conversions. 
 

1. Perform Keyword Research
2. Creating Compelling Ads
3. Improve Quality Score
4. Optimize Existing campaign with relevant or some negative keywords.
5. Use tools to craft SEM Campaign