Technical Preview version is targeted for developers. Developers use this version to checkout the latest features and report bugs if any. End users can also install this version to find out what's new in Windows 10. As it is a Technical Preview it will be unstable and chances of crashing are on the higher side. If anything goes wrong with your computer Microsoft will not be responsible.
You may also lose important data on your computer by installing this Technical Preview. Installing preview version is similar to installing a fresh OS, you will be erasing your previous OS and installing this new one. If you are familiar with installing an OS and do not have important data, you may go ahead and try it.
Please keep in mind that you may lose all your paid/free softwares by installing fresh OS (Technical Preview).