The knife attack at a western Sydney church has been labelled a "terrorist act", while the mass stabbing at a shopping centre on the weekend was not.
A 16-year-old boy is in custody at Christ the Good Shepherd Church in Wakeley, where was stabbed during a live-streamed sermon.
NSW Police said the attack was being investigated as a "terrorist incident".
So how does it differ from Saturday's incident when a 40-year-old man , killing six and wounding several others before he was ?
How is a terrorist act defined?
There is a legal definition of terrorism that's used to charge and prosecute people under terrorism legislation, said Emily Corner, an associate professor at the Australian National University's Centre for Social Policy Research.
Terrorism in Commonwealth law is defined as an act or threat that is intended to "advance a political, ideological or religious cause" and "coerce or intimidate an Australian or foreign government or the public".
Behaviour "causes serious physical harm to a person or serious damage to property, causes death or endangers a person's life, creates a serious risk to the health and safety of the public, or seriously interferes, disrupts or destroys an electronic information, telecommunications or financial system".
When asked on Tuesday about the two events, Australian Security Intelligence Organisation (ASIO) director-general Mike Burgess told reporters: "The simple answer is to call it a terrorist act you need indications of, well, information or evidence that suggest actually the motivation was religiously motivated or ideologically motivated.
"In this case, the information we have and the police have before us indicates that is strongly the case; that is why it was called an act of terrorism."
Police investigating the Bondi Junction mass stabbing are examining whether attacker Joel Cauchi was motivated by a hatred of women, saying it was in the attack.
Also on Tuesday, NSW Police Commissioner Karen Webb said the teenager arrested following the stabbing at Christ the Good Shepherd Church made comments indicating the alleged attack was religiously motivated.
She said: "We will allege [he] attended the church ... armed with a knife, and stabbed the bishop and the priest, and others were also injured.
"We believe there are elements that are satisfied in terms of religiously motivated extremism, and of course, the intimidation of the public through that person's acts.
"By attending that church, whilst it was being live streamed, intimidating not only the parishioners in attendance but those watching online and subsequently, those people who turned up to the church."
Burgess said the terror threat level in Australia would remain unchanged following the incident. It is currently set to "possible".
ASIO director-general Mike Burgess said the terror threat level in Australia would remain unchanged following an "act of terrorism" at a Sydney church. Source: AAP / Mick Tsikas
Is there a difference between a 'terrorist act' and 'terrorism'
In short, yes.
Terrorism is an umbrella term that refers to terror charges, while a "terrorist act" is a specific offence.
"You can be defined as a terrorist offender without ever conducting an act of violence," Corner said.
"You could be arrested for preparations for a terrorist attack, you could be convicted for financing other terrorist offenders. You can be convicted under the Terrorism Act for even searching terrorist content online."
NSW forensic police at the Christ The Good Shepherd Church in Wakeley, Sydney, on Tuesday. Source: AAP / Bianca De Marchi
"Traditionally, when we think of terrorism, it was about causing fear in populations as a way of creating some form of change," she said.
Terrorism laws in Australia have significantly expanded and multiplied since the 11 September 2001 attacks in the United States.
Unlike other Australian jurisdictions, in the Northern Territory, there is a specific offence of terrorism rather than a general definition of a 'terrorist act'.
Police powers and terrorist incidents
Declaring an event as a "terrorist incident" allows police to use extraordinary powers under NSW terror laws.
The laws give officers special powers to either prevent a terrorist attack from occurring within the next 14 days or to investigate a terrorist attack.
Without needing a warrant, police may stop and search people and vehicles, demand the disclosure of people’s identities, enter and search premises and vehicles, or establish a cordon such as a roadblock around a target area.
