DSL or ADSL is a fixed line Broadband Technology is the simple elaboration. Broadband is a general term refers to Broadband Access Technology in the Telecommunication world. DSL family consists of ADSL, ADSL2, ADSL2+, HDSL2 and VDSL2 etc. The general term broadband refers broadband access technology which gives us more bandwidth to access Internet or corporate Intranet via fixed line or wireless. In real world example it’s suitable to compare with multiple lane highway or motorway where many vehicles can travel at the same time. DSL is a general term to refer the technology but we commonly used ADSL and ADSL2+ for broadband access. DSL is also there in use as a corporate VPN access method, where users need equal bandwidth for upload and download. But generally in Internet world, the other flavour ADSL is mostly used where download and upload speeds are different.
DSL
DSL refers Digital Subscriber Line which is a fixed line broadband technology commonly used for broadband internet access. DSL technology can offer speed between 256 Kbps to 40 Mbps depends on different flavours of DSL as well as line condition and the distance between central office and the subscriber home. Line speed will drop with the distance from the central office or DSLAM (Digital Subscriber Line Access Multiplexer). Even though we refer it as DSL family but mainly ADSL is being used mostly. As you know, when you browse internet, most of the time you download things rather uploading. In a simple way of explaining I can say, when you browse internet every mouse click of yours will bring down some data from Internet and you expect it to come fast. By considering the user access and needs, ADSL technology is defined which is Asymmetric Digital Subscriber Line where download and upload speeds are different. DSL family have various definitions with different speeds such as ADSL, ADSL2, ADSL2+, VDSL, SDSL, SHDSL and VDSL2 etc.
Broadband
Broadband can be categorised into Fixed Broadband and Wireless Broadband. Wireless broadband could be either fixed wireless or mobile broadband. Basically broadband is a signalling method consist of wide range of frequencies divided into many channels. In simple terms you can think of this as a highway with multiple lanes. Earlier people were using narrowband technologies like dialup connection, which has only one lane equivalent road thus data rate is low and throughput also limited. In multiple lane highways many cars can travel at the same time similarly many packets could travel at the same time in broadband technology which eventually increases the speed. Broadband offering can be either wireless or wired but it offers a high bandwidth connection for you to access Internet or Corporate Intranet.
Broadband could be either fixed or wireless. Mostly used fixed broadband methods are ADSL, ADSL2, ADSL2+and Naked DSL. Most used wireless and mobile broadband methods are WCDMA, HSPA, HSUPA, HSDPA, HSPA+, LTE, WiMAX and CDMA Family.(3G and 4G Technologies)
Difference Between DSL and Broadband
(1) Broadband is a Family of Technology and DSL is one of them.
(2) DSL is a fixed broadband Technology.
(3) DSL is a subset of Broadband Technology Family. DSL have many flavours like ADSL,ADSL2,ADSL2+,VDSL,SDSL,SHDSL etc.