I would say that the growth and proliferation of information technology and communication has helped to encourage globalization in its most wide forms. The networking and ease within which new markets and forums for information dissemination can occur is part of the reason why globalization has become such a large part of our reality. Corporations and businesses can now embark on realistic visions of opening their centers up to new markets and revenue streams. This has happened with a growth of technology that has made global communication and interaction more possible and viable.
I think the other two answers have done a good job of mentioning the factors that cause globalization. Let me speak a bit to your secondary question.
Globalization itself really is a revolution in the same kind of way that the Industrial Revolution was a revolution. It is changing the way that people live throughout the world. For example, it is making people in developed countries much less secure in their jobs than they used to be.
Globalization is supported by theories and ideologies. Specifically, it is supported by the free trade theories/ideologies of traditional economists and most (American, at least) elites. These theories argue that free trade (which promotes globalization) is the best way to ensure maximum economic growth and prosperity.
Globalization refers, most frequently, to the phenomenon of growing interconnectedness of economic activities of different countries and regions of the world. However, this phenomenon is also occurring in other fields such as cultural and ideological influences. Globalization has, in this way, resulted in increasing involvement of multiple countries in design, procurement, manufacturing, selling, and use of products and services. These globalized operations has included economic activities such as ownership, financing, and management of capital resources. In the cultural and ideological field globalization has been manifest in greater exchange of cultural practices and ideas between different culture. This has resulted in movement towards development of cultures around the globe which are increasingly similar to each other.
As discussed above globalization is a phenomenon. The pace of change underlying this phenomenon has become quite fast in recent years. Yet it is not rapid enough to qualify globalization as a revolution. People may study globalization as a concept and develop theories regarding its various aspects. Individual companies may also have their own agenda and ideology regarding the extent to which they want to globalize, and how they want to go about it. But it would not be correct to classify globalization itself as things like a theory, ideology, revolution or an agenda.
Globalization as witnessed by us today is the result of a process that has developed over many thousands of years. With the development of practice of division of labour and of improved technology, the quantity of goods and services provided by a single production or business unit kept on increasing over many thousands of years, making it necessary to sell goods and services over much larger geographical areas. Similarly, it became necessary to source raw material and other resources required for production also from increasingly wider area. Industrial revolution and use of electric power quickened this pace of expansion of geographic sphere of economic activities. Technological developments in transportation and communication technology also made significant contribution to globalization by facilitating better communication and interaction between people of different regions and making transportation of goods cheaper and faster.