(Just in case you found a word or phrase that made no sense!)

Abbreviations

Full Name

Description

API

Application Program Interface

An automated method of transferring information between interfaces.

B2B

Business To Business

Businesses providing products and services for other businesses.

B2C

Business To Consumer

Businesses providing products and services for end consumers.

CPA

Cost per acquisition

How much it costs to acquire a conversion (be it a lead or sale).

HTML

Hyper Text Markup Language

The language that websites are, at least to some degree, written in.

ISP

Internet Service Provider

A company that sells web access to the general public. Example: AOL.

PFI

Paid For Inclusion

Search engines and directories allow advertisers to have their sites included for an inclusion fee (no guarantee of position).

PFP

Paid For Placement

Search results providers, such as Overture, allow companies to pay for their desired position, such as Number 1.

ROAS

Return on Advertising Spend

Same as for ROI below, but just accounts for investment in advertising.

ROI

Return on Investment

Monetary return for the money invested in a product, service or project (such as search engine marketing).

SERPs

Search Engine Results Provider

Some engines, such as Google, provide results for other sites that don't have their own search results such as in Google's case. AOL is an example.

SSO

Site Side Optimization

The process of optimizing the HTML code of a website for better search listings.

URL

Uniform Resource Locator

The official name for a website address such as...