1I achieve it with xml file.
2
3In TestNG is quite simple to do parallel testing. .
4First I create TestNG xml runner.
5Then I create suites or test tags in the xml runner. In these tag, I point to
6package or class I want to run.
7Then I add and option like parallel="test" into pom.xml, it means all tests
8will start running in parallel.
9
10Inside suite<> tag there are 3 attribute which is name,parallel and 
11thread count.
12
13name is mandatory, it has parallel beause we want to run different threads
14in this suite, we have thread count which is number of threads to use.
15
16There is also parameter annotation where I define name and value;
17In TestNG we can pass browser type from xml runner. In our java code, we use 
18@parameters annotations to read this browser type parameter.
19
20@Test
21@Parameters("browser")
22public void parameterized(String browser){
23if(browser.equals("chrome")){
24sout("open chrome")
25}else if...
26}
27
28How to check if your TestNG runs in parallel
29	inside methods you can use ==> Thread.currentThread.getId()
30	should have multiple different thread ids

1Cross Browser Testing: When we do crossbrowser testing we
2execute multiple test scripts on different browsers one by
3one. When one test executed/completed another browser
4would be invoked on the current browser.

1vCross Browser Testing: When we do crossbrowser testing we
2execute multiple test scripts on different browsers one by
3one. When one test executed/completed another browser
4would be invoked on the current browser.

1browser code is changing constantly 
2to test your products health on  the 
3				latest browsers, OSs, 
4a cross browser testing platform using
5mobile emulators & simulators, and real devices is helpful
6...unless you have a dedicated QA team of 20 - 30 people.
7