The present article gives a brief overview of space weather and its drivers. The space weather is of immense importance for the spaceborne and ground-based technological systems. The satellites, the power grids, telecommunication and in severe conditions the human lives are at risk. The article covers the effects of solar transient activities (e.g. Solar flares, Coronal mass ejections and Solar winds etc.) and their consequences on the Earth’s atmosphere. The space weather is the change in the conditions of interplanetary space because of the solar transient activities. We also discussed the importance of the solar wind which is a continuous flow of the charged energy particles from the Sun to the Earth in respect of the space weather. This article also put light on the Sun-Earth connection and effects of the space weather on it. The Earth’s magnetosphere, formed by the interaction of solar wind and Earth’s magnetic field behaves like a shield for the Earth against the solar wind.