The goal of equity may – not surprisingly – lead us to focus on those who are in need or at risk. We invest resources where we believe they are most needed and will have the greatest impact. Think back to our example of a race track. We are more likely to pay attention to the racers in the outside lanes, who have farther to go and need more energy to get there, than to the racers in the inner lanes, who can reach the finish line faster and with less effort. To offset disadvantage, we give the racers on the outside a head start.
But achieving equity also involves an understanding that advantage or privilege exists alongside disadvantage. Both must be changed in the quest for social justice.
Consider the example of affirmative action policies and programs, which give preference in hiring to minority groups – such as women and people of colour – who have been historically disadvantaged in the job market. The goal of affirmative action is to correct established patterns of discrimination. Some groups and governments have rejected this policy, arguing that it results in “reverse discrimination” against the dominant group – in this case men and White people. While affirmative action policies and programs deliberately favour some candidates over others, equity can only be achieved when those who enjoy privilege and power are willing or required to share it.
As Peggy McIntosh, a celebrated American feminist and anti-racist activist, wrote about male privilege in her influential essay White Privilege: Unpacking the Invisible Knapsack,
“I have often noticed men’s unwillingness to grant that they are over-privileged, even though they may grant that women are disadvantaged. They may say they will work to improve women’s status, in the society, the university, or the curriculum, but they can’t or won’t support the idea of lessening men’s. Denials, which amount to taboos, surround the subject of advantages, which men gain from women’s disadvantages. These denials protect male privilege from being acknowledged, lessened or ended.” 
Although McIntosh is speaking here about male privilege, power and advantage can be associated with many different factors, such as race and ethnicity, sexual orientation, language, ability, socio-economic status and income, religion, age, education and geography. 
Sources:  http://www.sascwr.org/files/www/resources_pdfs/anti_oppression/WHITE_PRIVILEGE.pdf;  http://www.safeatschool.ca/index.php?q=plm/equity-and-inclusion/understanding-sexism-racism-and-homophobia/racism/power-and-privilege-dynamics-in-racism