Intent

Intent intent = new Intent(MainActivity.this, ItemListActivity.class);

intent.putExtra("firstKeyName","FirstKeyValue");

intent.putExtra("secondKeyName","SecondKeyValue");

startActivity(intent);

// getIntent() is a method from the started activity

Intent intent = getIntent(); // gets the previously created intent

String firstKeyName = intent.getStringExtra("firstKeyName");

String secondKeyName= intent.getStringExtra("secondKeyName");