Algorithmic Trading Strategies refer to the execution side of a trade, in contrast to buy/sell decision making. Algo Strategy determine how you can fetch the best price under the constraints of market price, quantity and volume. Alpha Strategy decides when and what to buy, while the algorithmic strategy help to fetch the best price.
Thanks to SEBI, algorithmic trading is available to even the retail individual trader. For example, many brokers provide the free Bracket Order facility. It is the simplest example of algorithmic trading. Please refer the Conditional Orders article below on details regarding Bracket Order.