AIRAISA机票费用问题

想在AIRAISA上面订机票,可是费用种类搞不清楚,想请各位高手帮忙解释一下,英文单词基本能看懂,只是没看出来区别是什么?另外AIRAISA订的机票只是仓位费,不包括税款吧,那么税款是根据什么收的,在什么时候收取?谢谢!
费用种类如下(可能不全):
Fare Details

T FARE

- Bookings made with this fare only permit flight changes more than 48 hours prior to scheduled departure for a specified fee per guest per sector, plus any applicable difference in airfare.

- For full set of taxes, fees, charges and accompanying terms & conditions please read our Travel Requirements and our Terms & Conditions.

- This fare is capacity controlled. Seats offered at this fare are limited and may not be available on all flights.

- All fares are subject to change until purchased.

V FARE

- Bookings made with this fare only permit flight changes more than 48 hours prior to scheduled departure for a specified fee per guest per sector, plus any applicable difference in airfare.

- For full set of taxes, fees, charges and accompanying terms & conditions please read our Travel Requirements and our Terms & Conditions.

- This fare is capacity controlled. Seats offered at this fare are limited and may not be available on all flights.

- All fares are subject to change until purchased.

A FARE

- Bookings made with this fare only permit flight changes more than 48 hours prior to scheduled departure for a specified fee per guest per sector, plus any applicable difference in airfare.

- For full set of taxes, fees, charges and accompanying terms & conditions please read our Travel Requirements and our Terms & Conditions.

- No name changes are permitted.

- This fare is capacity controlled. Seats offered at this fare are limited and may not be available on all flights.

- All fares are subject to change until purchased.

P FARE

- Bookings made with this fare only permit flight changes more than 48 hours prior to scheduled departure for a specified fee per guest per sector, plus any applicable difference in airfare.

- For full set of taxes, fees, charges and accompanying terms & conditions please read our Travel Requirements and our Terms & Conditions.

- This fare is capacity controlled. Seats offered at this fare are limited and may not be available on all flights.

- All fares are subject to change until purchased.

I FARE

- Bookings made with this fare only permit flight changes more than 48 hours prior to scheduled departure for a specified fee per guest per sector, plus any applicable difference in airfare.

- For full set of taxes, fees, charges and accompanying terms & conditions please read our Travel Requirements and our Terms & Conditions.

- No name changes are permitted.

- This fare is capacity controlled. Seats offered at this fare are limited and may not be available on all flights.

- All fares are subject to change until purchased.