Update _index.md

Author: mokun

content/docs/guide/concepts/_index.md

@@ -1,10 +1,10 @@
 ---
 title: Simulation Concepts
-description: Overview of the concepts
+description: Overview of the Concepts
 weight: 1
 ---
-The MarsSim project is an autonomous simulation of life on Mars for Settlers living in Settlements.  
-Any Simulation is defined by a [Scenario]({{% relref "#scenarios" %}}) that defines the starting conditions.
+The Mars-Sim project is an autonomous simulation of human beings living on permanent Martian settlements.  
+A simulation can be constructed as a [Scenario]({{% relref "#scenarios" %}}) that defines the initial conditions.
 
 ## Entities
 
@@ -13,30 +13,31 @@ The simulation involves managing many entities and simulating the impact of time
 Time is simulated as a time pulse that applies a time duration to all entities, the frequency and duratino of these pulses can be altered by the end-user to drive a slower or faster simulation.
 
 ## Scenarios
-The Scenario provides the starting condition of a Simulation.
+The Scenario provides the starting condition of a simulation.
 The default installation provide a number of predefined [Scenarios]({{% relref "/docs/definitions/scenario" %}}) as well as the ability for a user to create their own can be created via the Scenario Editor tool.
-Each Scenario consists of 2 elements of information that the Simulation uses to build the initial set of entities; one for the exiting Settlements and the other future Settlements.
+Each scenario consists of 2 elements that the simulation uses to build an initial set of entities; one for exiting settlements and the other future settlements.
 
 ### Existing Settlements
 
-[Settlements]({{% relref "settlement" %}}) are the cornerstone of the Simulation as they are the main modelled entity. Each settlement that exist in the Scenario is defined as:
+[Settlements]({{% relref "settlement" %}}) are the cornerstone of the simulation as they are the main modelled entity. Each settlement that exist in the Scenario is defined as:
 
 - A unique name
-- A Settlement Template that specifies the physical layout of the Settlement.
+- A settlement Template that specifies the physical layout of the settlement.
 - Location on Mars Surface
 - The owning Authority
 - Population sizes
 - Optional Crew. If a crew is present; it's members will be seeded into the initial Settlement population. There are a number of pre-defined [Crews]({{% relref "/docs/definitions/crew" %}}); in addition new Crews can be created via the Scenario Editor.
 
-### Arriving Settlement Mission
+### Arriving Settlement Missions
 
-This defines any new Settlements that will be created in the future via a Resupply Mission. Currently there is no limit of the size of the supply mission, e.g. a 20 Building Settlement could arrive in one delivery.
-The Resupply stipulates all the existing Settlement details with the additino of the future arrival in terms of Sols.
+New settlements can be created in the future via a Resupply Mission. 
+A Resupply Mission may also stipulates specific resources needed for an existing settlement. 
+Currently, there is no limit to the size of a Resupply Mission, e.g. a total of 20 new buildings could arrive in one resupply delivery.
 
 ## Activities
 
-The daily life of Settlers and Robots are simulated at a micro level allowing them to perform Activities that may improve the settlements:
+The daily life of settlers and robots are simulated at a micro level allowing them to perform activities that sustain their settlement:
 - [Tasks]({{% relref "task" %}}) which are activities for an individual to perform.
-- [Missions]({{% relref "mission" %}}) these use a group of Settlers to work together to achieve an objective.
+- [Missions]({{% relref "mission" %}}) these use a group of settlers to work together to achieve an objective.