SEM, or Search Engine Marketing, is a digital marketing strategy focused on promoting websites by increasing their visibility on search engine results pages (SERPs) through paid advertising. Unlike SEO, which focuses on organic (non-paid) rankings, SEM involves paying for ads to appear alongside or above organic search results.

Key components of SEM include:

Pay-Per-Click (PPC) Advertising: The most common form of SEM, where advertisers pay each time a user clicks on their ad. Google Ads (formerly Google AdWords) is the most popular platform for running PPC campaigns.

Ad Auctions: In SEM, ads appear based on an auction system. Advertisers bid on keywords, and search engines display ads based on various factors like bid amount, ad quality, and relevance to the user's query.

Keywords: Just like SEO, keywords are crucial in SEM. Advertisers choose relevant keywords that users are likely to search for, and their ads will appear when those keywords are entered in search engines.

Ad Copy: The text or visual content of the ad is vital in attracting clicks. Crafting compelling ad copy, along with a clear call to action, can improve ad performance.

Landing Pages: Once a user clicks on an SEM ad, they are directed to a landing page, which should be optimized to convert visitors into leads or customers.

SEM offers immediate visibility and control over when and how your ads appear. It's a great way to drive targeted traffic to your site, especially for competitive keywords where ranking organically might take time.