In this chapter, we have examined the intricate connections between human fertility and global development by examining various factors that contribute to this complex relationship. Understanding the interplay between these global dynamics and Total Fertility Rate is crucial for societal planning. This comprehension serves as a foundation for crafting strategies to address population-related challenges and implement effective development measures. Within this context, we have analyzed four key proposals: (a) the correlation between TFR and population metrics, (b) the relationship between TFR and GDP, (c) the connection between TFR and Human Development Index, and (d) the interrelation between TFR and social factors. Through these studies, we gain insights into how TFR impacts a country’s economic landscape and social fabric. Finally, we conclude by identifying the reasons behind the decline in fertility rates.