As physical systems are cooled down, their properties may no longer be described in classical terms, and we enter a quantum regime. Perhaps the most fascinating quantum property is entanglement. Recently, with understanding of entanglement between a few particles, many-body entanglement has received great interest in such varied fields as condensed matter, cosmology and quantum information. Indeed, the scaling of entanglement in large systems is a sensitive measure of the nature of interactions and phases. In contrast with typical thermodynamical behavior, the entanglement entropy of a sub region in a physical system often grows as it's boundary area, and not as its volume. In this talk, I will describe such “area laws”, their appearance and relation to quantum phase transitions. I will also discuss a yet more detailed analysis of such entanglement, known as entanglement spectrum. Finally, I will exhibit a universal relation between entanglement and statistics of current flowing through a quantum point contact, which provides a way to experimentally measure entanglement entropy.