The state of emergency is a temporary measure that grants governments broad powers to deal with a crisis. It can alter government operations, order specific action by citizens and suspend regular civil rights. The state of emergency is a powerful tool that can be used to address the current COVID-19 pandemic and future public health threats.
States of emergency give governments broad powers to manage a crisis and can be used to restrict travel, impose curfews, take control of infrastructure like broadcasting, power distribution, utilities etc. They can also commandeer and ration goods like food, water and shelter and generally instruct private businesses to aid with certain efforts. They can also streamline procedures, removing traditional checks and balances to act more quickly.
A state of emergency can be triggered by war, attacks by foreign powers, terrorism that threatens the security of a place in the UK or events that could cause serious damage to human welfare or the environment. It allows the British Crown (on advice of the Privy Council) to introduce emergency regulations that can last up to thirty days. The government can suspend many rights, but not basic human rights such as freedom of speech and religion.
The declaration of a state of emergency differs from lockdowns implemented in the US and Europe, as laws restricting private rights are not in place. It does, however, grant the executive branch of government a wide range of powers to deal with a public health crisis.