Both internal and external modems are availabe and your choice shouldn't affect the speed of modem. There are two types of modem to consider for either dialup or broadband connections.
Broadband modems allow you to connect to a broadband activated line and obtain speeds typically 10x faster than a standard modem. If broadband is available in your area, it is highly recommended that you connect to the internet through broadband rather than a dial up.
For more information on broadband or ADSL, visit our Internet Resource Centre here.