You can pass values from one activity to another activity using the Bundle. In your current activity, create a bundle and set the bundle for the particular value and pass that bundle to the intent.
Intent intent = new Intent(this,NewActivity.class);
Bundle bundle = new Bundle();
bundle.putString(key,value);
intent.putExtras(bundle);
startActivity(intent);
Now in your NewActivity, you can get this bundle and retrive your value.
Bundle bundle = getArguments();
String value = bundle.getString(key);
You can also pass data through the intent. In your current activity, set intent like this,
Intent intent = new Intent(this,NewActivity.class);
intent.putExtra(key,value);
startActivity(intent);
Now in your NewActivity, you can get that value from intent like this,
String value = getIntent().getExtras().getString(key);