I just saw that you asked another question about this topic. Once again, you can find a lot of information on each of Hofstede's culture dimensions on the Geert Hofstede website and read explanations of each dimension once you have done a country comparison. These country comparisons are free.
For now, here is a quick explanation of the three dimensions you mentioned:
1) Masculinity: This dimension has nothing to do with men and women. In other culture models, this dimension is often referred to as competitive (masculine) vs cooperative (feminine). Hofstede describes 'high masculinity' cultures as driven by competition, achievement, and success, (e.g. the US), whereas 'low masculinity' cultures value caring for others and quality of life higher (e.g. the Philippines).
2) Uncertainty Avoidance: Cultures with high uncertainty avoidance tend to be inflexible, don't like changes, and show a high level of planning and organizing, because chaos is unwanted and must be avoided at any cost (e.g. Germany). On the other hand, cultures with low uncertainty avoidance tend to be more flexible, do less planning and organizing, and can deal with changes more easily, because chaos is expected and can be managed (e.g. Singapore).
3) Individualism: In cultures with high individualism, "I" is more important than "we", and unlimited personal opportunities and freedom are highly valued. It is no surprise that the US has one of the highest scores on the individualism index as a country that declares "life, liberty, and the pursuit of happiness" an unalienable right in its Declaration of Independence. The opposite are highly collectivistic cultures, such as China, which place by far more importance on the "we" than on the "I" and value unquestioning loyalty more than anything.
I hope this helps!