What is the difference between virus and spyware?

Virus : A computer virus is a program capable of continually replicating with little or no user intervention.
Typically, a piece of code causes damage to your computer either by deleting or corrupting files.
A virus can also interfere with computer operations by multiplying itself to fill up disk space or randomly access memory space, secretly infecting your computer.
Often viruses are disguised as games, images, email attachments, website URLs, shared files or links or files in instant messages.
Spyware : Spyware is malicious computer program that does exactly what its name implies-i.e., spies on you.
After downloading itself onto your computer either through an email you opened, website you visited or a program you downloaded, spyware scans your hard drive for personal information and your internet browsing habits.
Some spyware programs contain keyloggers that will record personal data you enter in to websites, such as your login usernames and passwords, email addresses, browsing history, online buying habits, your computer's hardware and software configurations, your name, age and sex, as well as sensitive banking and credit information.
Some spyware can interfere with your computer's system settings, which can result in a slower internet connection.