A grant is a sum of money which is made available to an individual or institution in order to advance the goals and purposes of the organization making the money available. It does NOT need to be paid back, and there are many grants to choose from.
In general, grants come from three sources: 1) government agencies, 2) private foundations, 3) corporate giving programs. Government agencies grant money mainly to organizations that can assist it to realize the objectives for which the agency was created. (For example, the Department of Agriculture makes money available to strengthen the rural economy.) Private foundations are established by wealthy individuals for charitable purposes. (For example, The Bill & Melinda Gates Foundation funds medical programs to help people in Third World countries. It also makes information technology available to communities that lack access to computers and the Internet.) And finally, corporations sometimes establish their own charitable foundations or community outreach programs.
A good starting point for identifying various kinds of assistance is using programs that will give you the information you need is at: www.grantgenerator.com.