First one is the short version. Second one is the very short version.
Feel free to read both but pay particular attention to the second one, it's the one that really matters.
The new act protects key rights for suspects including access to legal advice and abolishes the separate concepts of arrest and detention replacing them with a single statutory power of arrest without warrant where there is reasonable grounds for suspecting a person has committed, or is committing, an offence.
It also creates new investigative tools for the police, with scope for investigative liberation and post-charge questioning.
Where police suspect someone but don’t have sufficient evidence to charge them, investigative liberation will give them the option to attach conditions to the person’s liberation for a period up to 28 days while they continue to investigate, with the power to rearrest the person for the same offence as many times as may be needed within the statutory time limits.
If there’s no evidence you've done anything wrong, the police must let you go (just as before). However, now they can impose, for a month, restrictions on where you can go and who you can contact etc. Breach these unilaterally imposed conditions and you will be charged with breaching the conditions and possibly imprisoned.
Hmmm, so how long before we have thousands of innocent members of the public who have done nothing wrong and have not been charged with anything still placed under control of the police?
History tells us that every time Police get new powers they always abuse those powers. Always.
This is all gonna end in tears, you can just see it coming.