Modern geography has come a long way and is today an all encompassing field of study. It covers the study of spatial arrangement of phenomenon that have shaped the surface of the earth, the interrelationship between man and environment and the research related with earth sciences.
It is important to note that this field is chiefly concerned with spatial arrangement or distribution of things. It also tries to find reasons for: why these arrangements have surfaced, what factors have led or will lead to the changes in the spatial distribution and with what effect. For example, it tells us the factors that have led to location of industry at a particular place and if there was a change of location, what factor led to that.
Geography is different from Geology. Geology deals with the interior of the earth's crust unlike Geography which is a study of the things and phenomena on the surface of the earth. Similarly, it can be distinguished from History in that the latter studies things as have happened over a passage of time.
It is broadly categorized into two parts: physical and human. The physical aspects deal with the landforms like the mountains, plains, deserts, plateaus, and the processes which form these landforms. These physical features evolve over a long period of time.
The human aspect studies the interrelationship between man and earth. It covers cultural (ethnicity, religion), geo-political, historical, economic and other aspects. These change as compared to the physical ones in a comparatively short time frame, say, two or three decades. For this reason, you will find that most of the geography textbooks are not rewritten or revised. Mostly, it is the used textbooks that keep changing hands.
It is ironical that this stream is underrated as a career choice even as the practical applications of this body of knowledge finds great use in our everyday lives. Whether it is the city map at your home or the modern day GPS device in your car, these are the result of technological innovation in this area. And, it is also relevant while studying other subjects like history, polity, and environmental sciences in schools and colleges. Further, while opting for careers in travel and tourism, journalism, digital mapping, urbanization studies, and demographics, the knowledge of Geography is essential. Some of the jobs even require a degree in the field. You can simply read any relevant book on it. If budget is a constraint, you can even go for less expensive used textbooks.
With the development of geographical thought and quantitative revolution, a new study called Geometrics has evolved. Its continuous evolution has enabled the measurement of various phenomena using advanced devices. Modern remote imaging, digital mapping technologies, and cartography have led to development of Geographical Information Systems and Global Positioning Systems. These have proven to be invaluable for resource mapping, defense and geo-political purposes, and for maintaining law and order.
It is true; geography is a vast area of study.