 -- Before President Bill Clinton left office, he started planning for his transition out of the White House by doing what many before him did -- starting a public charitable organization with the primary function of building the Clinton Presidential Library. He originally named it the William J. Clinton Foundation.

But by the time he left office in 2001, his foundation was starting to grow rapidly, pioneering HIV/AIDS initiatives and attempting to combat global health crises with the help of governments, nonprofit groups and influential people. And in 2005, the Clinton Global Initiative (CGI) was started by former White House aide to Bill Clinton, Doug Band.

Now, the various iterations of the Clinton Foundation are coming under scrutiny as part of the 2016 presidential campaign as Hillary Clinton runs for the White House.

Here is a breakdown of the various branches of the famous family's foundation.

What Is the Clinton Foundation?

The foundation has since become one of the fastest growing non-governmental organizations in the world and with that growth it fell under much scrutiny from the moment President Obama nominated Hillary Clinton as secretary of state at the start of his administration.

The possibility that donations to the foundation might influence foreign policy decisions was a concern of the Obama administration and to allay those concerns, a memorandum of understanding was signed and consequently shared with Congress. The foundation then began publicly disclosing and updating its list of donors on a quarterly basis. And since Hillary Clinton finished her tenure as secretary of state, the foundation changed its name to the Bill, Hillary and Chelsea Clinton Foundation, and Hillary and Chelsea Clinton were added to the board. President Clinton announced in a letter to foundation staff on Monday that the foundation would be renamed again as simply the Clinton Foundation if Hillary Clinton were to become president.

The Clinton Foundation is a nonprofit 501(c)3 corporation and is an operating foundation, which means that the money it raises can go to its various programs, rather than simply as grants to other nonprofits. It is not primarily a grant-making entity like many other foundations, although it does give grant money to other projects.

The foundation has nine thematic initiatives, including economic development, which is dedicated to building agricultural projects for farmers; the "No Ceilings" initiative, which focuses on including women and girls, and fights to decrease the wage gap; and they lead various health initiatives.

Foundation officials have maintained that since Hillary Clinton was tapped to be secretary of state, money raised by the foundation is spent directly on their various programs. To maintain a sense of transparency, the foundation also regularly reports the progress of it projects online.

What Is the Clinton Global Initiative?

The goal of CGI was “creating a global network of citizen activists who reach across the divides of our interdependent world to build real communities of shared opportunities, shared responsibilities, and a genuine sense of belonging,” wrote Clinton in his 2007 book "Giving."

The CGI is an arm of the greater foundation that helps to link up partners with a particular need or project and works to make sure those needs are met over a given period of time and the success of those commitments is carefully measured and assessed.

In his book "Giving," the former president wrote that he wanted CGI meetings to convene for at least ten years. The former president announced on Thursday to staff that this will be the 12th and final year of the initiative arm of the foundation.

In an interview with NPR on Tuesday, Clinton Foundation President Donna Shalala said that the foundation would not shut and would in fact move many of its efforts to other organizations. "We're going to spin off or find partners for many of our programs," Shalala said.

According to Shalala’s NPR interview, restructure planning of the foundation began a year ago and she said many of the foundation's programs would become separate non-governmental organizations. Without giving specific names, Shalala said that the partner organizations will continue the work that was started by the foundation. She also admitted that President Bill Clinton is also "coming off any relationship with any of these spin-offs or these new partner organizations” and will not be involved with any of the spin-offs.

At last year's annual CGI meeting, Clinton Foundation officials told ABC News that Chelsea Clinton is poised to take on a more central role in the Clinton Foundation, should Hillary Clinton become the next president. At that same meeting, Bill Clinton promised that his work with the foundation would continue even without him.

"Ten years from now, somebody will be here,” Clinton said at the annual meeting in 2015. “I'd like it if I could outlive every man in my family and be one of them, but we'll see."

President Clinton told his staff on Thursday that he would officially step down from the board of the Clinton Foundation if Hillary Clinton becomes the next president and a spokesperson for Chelsea Clinton told ABC News that she will stay on the board of the foundation regardless of the outcome of the election.

A representative of the foundation said that over 300,000 donors from around the world have given to the foundation, most of those donations are under $250.

The foundation lists its donors on its website, but not its contributors, who are classified in a different way. Donors give money to specific programs to the foundation and contributors pay fees related to attendance at foundation events such as Clinton Global Initiative.

What Is the Clinton Family Foundation?

The Clintons also have a personal, private foundation that they use to make their own charitable donations to organizations such as New York Public Radio, the Wildlife Conservation Society, the Children’s Defense Fund and more, according to an aide from Hillary Clinton’s campaign.

They also use funds from this much smaller foundation to donate to the larger Clinton Foundation and its programs.

The Clinton Family Foundation has given between $5 million and $10 million to the Clinton Foundation. According to Hillary Clinton’s tax returns, at least 98.5 percent of the Clintons’ charitable donations have gone directly to the Clinton Family Foundation or Clinton Global Initiative.