Explain the stages of the Product Life-Cycle?

An alternative is the5-6 stage model:

1. Initial stage
2. Growth
3. Maturity
4. Saturation
5. Decline
6. Relaunch (if applicable)

Explenation: 

1. Initial stage:

• High cost for marketing & advertisement, creating demand
• Slow sales volume, little turnover, little profit
• Little or no competition

2. Growth stage

• Increasing sales and profit
• Lower costs due to increased production
• Increasing competition (free-riders, me-too-products)
• High costs for advertisement

3. Maturity stage

• Highest profitability and market share
• Sales volume peak
• Stagnation, little or no mentionable growth

4. Saturation stage

• Stagnation
• Decreasing profit

5. Declining stage

• Market and market share decrease
• Little or no profit
• Product is "dying"

6. Relaunch

• Modification and repositioning of the product

Initial stage, growth stage, maturity stage and the declining stage.