An inline frame acronym as iframe is used to insert another document with in the current HTML document or simply a web page into a web page by enabling nesting.
Select iframe by id
driver.switchTo().frame(“ID of the frame“);
Locating iframe using tagName
driver.switchTo().frame(driver.findElements(By.tagName(“iframe”).get(0));
Locating iframe using index
frame(index)
driver.switchTo().frame(0);