Globalization is a massive topic which is studied at length and as a result any answer here is going to be just the tip of the iceberg. There are many different types of globalization, the three main subtypes are: Economical, Cultural/social and Political.
Economic and technological globalization is where goods and services are now provided by large corporations on a worldwide level. This is done by utilizing resources in countries where they are more economically viable as well as moving raw materials to where they can be transformed into saleable goods. Through the rise of container ships, the easy transport of any type of product makes it feasible to transport goods around the world to increase a profit margin. This also includes the opening up of borders to allow labor forces to work outside of their home countries, as in the EU, although there are still considerable boundaries for workers in the rest of the world.
Cultural globalization comes from the rise of large media conglomerates that saturate the airwaves with a particular point of view and corporate entities like Coca-Cola, McDonalds and Starbucks who homogenize society and take away from local culture and traditions. This could be argued to be the western, more developed countries taking advantage of markets which were not otherwise available. It is often done with a young population in the developing country who are happy to have, what they consider, the chance of the spoils of the West.
Political globalization refers to institutions like the UN, World Bank and IMF who have global influence. These institutions can affect how individual nation states act and supposedly do it from the point of view of the good of the whole.