Google Earth has always been free. Google Earth Pro was $400 annually up until 2015 but now that is free also.
You can download either Google Earth or Google Earth Pro and freely use them from your computer.
UPDATE: As of Google Earth Pro 7.3.0, Earth "Free" and Pro have now been combined into a single product, Earth Pro. See https://support.google.com/earth/answer/40901?hl=en
Yes, you have to pay unless you can hack
Unfortunately, a littly bit :( Google sends you a SMS wich you have to pay for When they send you the SMS you can use the code from the SMS to make a GMail account Its to prevemt from Spam.
The free version of Google Earth does not need a license key. A license key is required for Google Earth Pro. You can download Google Earth Pro and request a free 7-day trial license after which you need to pay an annual fee to continue to use it.
Google Maps does not provide the historical imagery view feature that is available in Google Earth. To see past imagery you must use Google Earth. See related details in link below.
google earth 3d is called google earth 5.0
You must either download/install the desktop version of Google Earth on your computer or visit a website using the Google Earth API and download the web browser plugin when prompted. In both cases you must download some software to your computer to run Google Earth. The browser plugin, however, doesn't require administrator privileges, which the desktop install does. Googles Maps on the other hand does not require any software or plugin downloading. You can try out the web-browser plugin version of Google Earth visiting the URL in related links below.
google earth
I guess it is free to use however, you cannot distribute it on your own. In free version you cannot integrate your GIS data but there are another versions like Google Earth pro and Google Earth enterprise.
No you do not have to pay for a Google reader subscription.
A Google Earth plug-in is a plug that automatically brings you to Google Earth.Answer#2Actually, the Google Earth plugin is an embedded version of Google Earth that runs within the web browser.
Google reported in 2011 that there were over a billion downloads of Google Earth. That includes downloads of the Google Earth desktop client, mobile apps and the Google Earth plug-in.
One uses Google Earth to get directions as Google Earth provides geographical information about places on the Earth. Google Earth was released twelve years ago in 2001.