What is Net Neutrality?
Network neutrality is a principle of network architecture obliging ISPs to treat data packets that flow through their networks in an isonomic manner, under no discrimination due to content, origin, destination or application type. Early ideas over the matter emerged in the 2000s, a period in which broadband expansion and the advent of new generations of mobile Internet increased the number of connected devices at a lot faster pace when compared to the physical expansion of telecommunication networks (e.g. VoIP applications competing with traditional telephony services), with evidences that ISPS were throttling traffic from applications that could be detrimental to their business interests.
There are at least three manners to discriminate some specific content or application over the Internet: blocking, throttiling, or charging a different price for access.

Blocking
Not only does content blocking occur in the private sector, but also in countries with strict Internet censorship, at the initiative of governments either directly or indirectly under the control of the State, such as China. such as China.

Throttling
Speed reduction occurs when a particular application is not loaded at the speed of other applications. This is due to several reasons: to decrease the quality of a service competing with traditional telephony services (e.g Skype and WhatsApp); to facilitate users' access to a competing service; to reduce bandwidth consumption in heavy applications (such as youtube); or even to prevent access to services which may violate intellectual property rights (Bittorrent). Although there are several reported cases worldwide of this type of discrimination, many of them may be hidden, hence, increasing the difficulty a user has in identifying patterns of discrimination.

Price Discrimination
Finally, ISPs can also discriminate through different prices for their service or application. This differentiation may come from charging any additional fees for access to certain content, as with cable TV. Also, ISPs can provide free access to some applications specifically chosen by providers, which that can hamper competition between similar applications.