Basically, Hobbes believes that people give up much more of their liberty to the government than Locke does. This is because Hobbes has a much more negative view of human nature than Locke does.
Both Hobbes and Locke believe that people in the state of nature need to band together and create a society. Both believe that this society will protect people's lives from other people. However, Hobbes believes that people must give up much more in order to be protected than Locke believes.
To Locke, people band together under a government that rules with their consent. The government exists only to protect their life, liberty, and property. The government's ability to regulate the people is severly limited in many cases.
To Hobbes, the government can do anything it wants. The people give up their rights to an absolute ruler. The ruler has to be absolute if society is to survive.
The major difference, then, is that Locke envisions a very limited government while Hobbes believes in the need for absolute monarchy.
The difference between Hobbes' theory of government and that of Locke is rooted in their very different views of human nature. Hobbes believes that humanity in a state of nature lives in a state of perpetual conflict, famously describing such a life as "nasty, brutish, and short." Thus Hobbes sees government as a way of restraining our naturally selfish and unruly natures so that we can live and work together. Thus he advocates authoritarian government in which people give up personal liberty in exchange for order and safety. He argues that absolute centralized power is the only way to achieve this.
Locke, on the other hand, argues that a human is by nature a "tabula rasa" (blank slate) and that people are shaped by their environment and educational systems. Rather than government functioning to restrain the inherent evils of human nature, he sees the world as more benign, with government fostering cooperation and only restricting liberty where necessary for society to survive. He thus advocates a more tolerant and limited form of government.