This review discusses recent advances in the physics of thin-film ferroelectric oxides, focusing on their unique properties in thin-film form. It covers the application of ferroelectric thin films in electronic devices, the physics behind their performance and failure, first-principles computational approaches, the role of strain in determining their properties, and emerging possibilities in nanoscale ferroelectrics. The review emphasizes the importance of understanding the behavior of these materials at the atomic and electronic level, especially for ultrathin films. It also discusses the challenges and opportunities in the development of ferroelectric memories, including their reliability, design, and integration with complementary metal-oxide semiconductor (CMOS) technology. The review highlights the potential of ferroelectric materials in non-volatile memory technologies and their use in devices such as DRAMs. It also explores the physics of ferroelectric field-effect transistors (FETs), the effects of strain on ferroelectric properties, and the behavior of domain walls in ferroelectric materials. The review concludes with a discussion of the challenges and future directions in the study and application of ferroelectric thin films.This review discusses recent advances in the physics of thin-film ferroelectric oxides, focusing on their unique properties in thin-film form. It covers the application of ferroelectric thin films in electronic devices, the physics behind their performance and failure, first-principles computational approaches, the role of strain in determining their properties, and emerging possibilities in nanoscale ferroelectrics. The review emphasizes the importance of understanding the behavior of these materials at the atomic and electronic level, especially for ultrathin films. It also discusses the challenges and opportunities in the development of ferroelectric memories, including their reliability, design, and integration with complementary metal-oxide semiconductor (CMOS) technology. The review highlights the potential of ferroelectric materials in non-volatile memory technologies and their use in devices such as DRAMs. It also explores the physics of ferroelectric field-effect transistors (FETs), the effects of strain on ferroelectric properties, and the behavior of domain walls in ferroelectric materials. The review concludes with a discussion of the challenges and future directions in the study and application of ferroelectric thin films.