What President Obama's executive actions on guns can do
The White House has announced numerous executive actions aimed at decreasing gun violence in the US.
President Obama has said the actions are in his executive authority and that they will save lives.
The president said he recognises that the measures will not prevent all violence or mass shootings in the country.
"This is not going to solve every violent crime in this country," Mr Obama said. "It's not going to prevent every mass shooting; it's not going to keep every gun out of the hands of a criminal. It will potentially save lives and spare families the pain of these extraordinary losses."
What do the executive actions include?
- All sellers must be licensed and conduct background checks, overturning current exemptions to some online and gun show sellers
- States must provide information on people disqualified due to mental illness or domestic violence
- FBI will increase workforce processing background checks by 50%, hiring more than 230 new examiners
- Congress will be asked to invest $500m (£339m) to improve access to mental healthcare
- The departments of defence, justice and homeland security will explore "smart gun technology" to improve gun safety
Who will be affected?
Under the executive action, more sellers would have to register as federally licensed gun dealers, eliminating certain loopholes.
Gun sellers can be divided into two categories: federal firearms licensees and private sellers. The former is regulated by the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF), which conducts background checks.
Private sellers, on the other hand, largely do their business without government oversight.
There is much talk about the "gun-show loophole", but in reality, the majority of vendors at gun shows are licensed dealers, and unlicensed sellers meet at the shows to bring attention to their collections or sell guns.
Gun sellers also currently evade background checks by selling guns online and in other settings.
Some people sell guns out of their personal collection simply to get rid of ones they are not using anymore, and those people are exempt from the background check requirement. But many profit from selling guns without a license and are involved in illegal gun trafficking. Because current law is vague, it is hard to prosecute these cases, and many go unchecked.
"Those folks who are engaged in the business illegally are a small share of all unlicensed gun sellers, but they are contributing disproportionately to gun trafficking," Ted Alcorn, research director for gun violence prevention group Everytown for Gun Safety, told the BBC.
According to research by Mr Alcorn's group, just last year 600,000 guns were for sale on a website called ArmsList by dealers not under the federal background check requirement.
What's in a background check?
Most include: arrests, felony or misdemeanours, court records, warrants, sex offences and incarceration records.
If the FBI needs to follow up on something in a background check, they currently have three days to do it. If the agency does not do so in three days, the person wishing to buy a gun can go ahead with a purchase.
This is how Dylann Roof, who police say killed nine people in Charleston, South Carolina, in June obtained a gun despite having a drug charge.
The new actions would allow for 24/7 background checks, eliminating the loophole that people who should not be able to get guns are able to do so because the FBI did not process their check fast enough.
Will the actions make a difference?
"It's absolutely going to make a difference," Mr Alcorn said. Someone illegally engaged in gun selling can put hundreds of firearms in illegal markets in the US in cities like Chicago and New York City, he said, with "devastating consequences" as a result.
"Clarifying the law will make a difference... it's also a symbolic gesture," Mr Alcorn said. "In face of Congress' refusal to take meaningful action, [Obama] is willing to put his team's attention and creativity into determining the ways the executive branch can make a difference."
The actions do not limit capacity on ammunition magazines or ban assault rifles, which gun control groups have repeatedly called for. Still, many are pleased with the actions.
Mr Obama has "answered the calls of moms, gun violence survivors, community leaders and every day advocates across the country who worked tirelessly to support the President in taking meaningful action to prevent gun violence," said Shannon Watts, founder of Moms Demand Action for Gun Sense in America.
The National Rifle Association, a powerful group that ranks lawmakers on how gun-friendly they are which opposes nearly every new piece of gun legislation, tweeted that Mr Obama's "rhetoric does not match his record" and that the group had been "calling for the full enforcement of the law for... a while now."
"Funny how @POTUS invokes civil liberties while trying to restrict one of them," the group tweeted.
What are the caveats?
These are executive actions, not orders, meaning they are not legally binding.
"They represent less formal guidelines that the ATF will implement for gun dealing," gun violence news website the Trace explains. "Which means that Obama may wind up facing criticism not just from those who think he's overstepped, but those who could conclude he has not gone far enough."
The funding for mental health services will require congressional approval, and the funding to hire more agency workers may as well.
Some of the actions are likely to be challenged in court.
These actions can all be overturned by the next president-and the Republican candidates are all promising they would do so on day one.
More on US gun debate
Why Obama is powerless - the roadblock at Congress
Are you mad or criminal? - the question a gun seller asks
Texas women and their firearms - a photographer taught to shoot at an early age
Do tighter gun laws work? - a state where guns are a way of life
Guns at home - the question parents hate to ask before a playdate