The diffusion of cancer cells from the primary tumor site into a secondary organ of the body is called metastasis. Metastasis is a feature of malignant cancerous cells and is the cause of cancer treatment failure as well as most cancer-related deaths. Although many studies have been done on various aspects of the complex phenomenon of cancer metastasis, our knowledge is still very incomplete. Tumor biology research has revealed some of the molecular basis of this process, which can help find targets for molecular therapy to stop or potentially reverse the growth and metastasis of cancer. In order to overcome interstitial challenges and ensure a successful invasion, infiltrating tumor cells interact with the other neighboring cells as well as the various cells and molecular components present in the surrounding microenvironment. Identification of these interactions has improved some understanding of the biological principles of metastatic cells that control their flexible behavior. In fact, this is facilitated by the intrinsic genetic properties of cancer cells along with the many various epigenetic stimulants within their microenvironment. More research on the biological mechanisms beyond the metastatic process is thus important to find efficient treatment strategies for a successful intervention. In this chapter, recent advances and the latest findings on the characteristics of cancer metastasis will be addressed.