Up until 1994, the South African government was dominated by the country's white minority, oppressing the far larger black majority in the country, The system of laws and actions used by this government to oppress these blacks was known as apartheid. Under apartheid, the entire life of South Africans was predetermined by their skin color. Blacks couldn't vote, hold any public offices, and were only given access to substandard schools and hospitals. They had little choice of where they could work and their freedom of movement was tightly restricted. Any blacks who dared to protest this humiliating treatment were either jailed or killed by the government. In virtually any kind of imaginable comparison, Israel's treatment of its Arab citizens is completely incomparable.
Arabs are not only allowed to vote in elections, but they can even run in them. As a matter of fact, the United Arab party is the third largest in the Israeli government and while they're some of Israel's staunchest critics, they're given a fair and equal platform from which to voice their opinions. Arabs have no job restrictions and can be found holding high positions in businesses and Israel's judicial system. It was an Arab-Israeli judge who was tasked with overseeing Israel's recent elections, and it was an Arab who won the title of "Miss Israel" in 1999. It's also important to point out that they're given full and unrestricted access to Israel's health and education systems. From a legal standpoint, the only difference Jewish Israelis have from their Arab counterparts is that the latter isn't required by law to serve in the military, although many of them volunteer to serve anyway. Arabs living in Israel are freer than any other arabs in the Middle East. It doesn't take much research to see what happens when Arabs protest the government in other parts of the Middle East (take Syria or Iran for example).
Sixty-seven years ago, Israel was founded on the values of western-style freedom and democracy. To this day, Israel is still that same democracy it was established to be and remains the only true democracy in the Middle East. With regular elections, freedom of religion, a free media, and rich ethnic diversity, Israel is one of the only countries in the entire region where all of its citizens, regardless of their faith or gender, can enjoy everything that society has to offer them, and protest if they disagree with it. There are other countries in the Middle East that practice an "apartheid" style oppression, but the claim that Israel is an apartheid state is completely baseless and is nothing more than an attempt to paint Israel in a bad light.