

Search engine optimization (SEO):
Search engine optimization (SEO) is the art of understanding search engines and and using that knowledge to make a website rank high on search engines.
SEO is the combination of tactics and strategies, including, but not limited to, optimization of information architecture, usability, content focus, audience targeting, design, development, keyword research, keyword placement, link building, social media marketing and any other online or offline branding/marketing elements that support the goal of receiving more traffic from search engines.
Search engine marketing ( SEM):
Search Engine Marketing (SEM) is now synonmymous with Search Engine Advertising. It used to be an umbrella term referring to various techniques for acquiring website traffic from search engines, such as:
* Search Engine Submission
* Search Engine Optimization (SEO)
* Pay Per Click (PPC) advertising
Location based services ( LBS) :
A location-based service (LBS) is a software application for a IP-capable mobile device that requires knowledge about where the mobile device is located. Location-based services can be query-based and provide the end user with useful information such as "Where is the nearest ATM?" or they can be push-based and deliver coupons or other marketing information to customers who are in a specific geographical area.